EQR 10-K Fiscal year ended Dec. 31, 2009

Table of Contents

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

For the Fiscal Year Ended DECEMBER 31, 2009

OR

For the transition period from to

Commission File Number: 1-12252

EQUITY RESIDENTIAL

(Exact Name of Registrant as Specified in Its Charter)

(312) 474-1300

(Registrant’s Telephone Number, Including Area Code)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes x No ¨

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes ¨ No x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes x No ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes x No ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter) is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).    Yes ¨ No x

The aggregate market value of Common Shares held by non-affiliates of the Registrant was approximately $5.9 billion based upon the closing price on June 30, 2009 of $22.23 using beneficial ownership of shares rules adopted pursuant to Section 13 of the Securities Exchange Act of 1934 to exclude voting shares owned by Trustees and Executive Officers, some of who may not be held to be affiliates upon judicial determination.

The number of Common Shares of Beneficial Interest, $0.01 par value, outstanding on February 19, 2010 was 281,884,878.

Table of Contents

DOCUMENTS INCORPORATED BY REFERENCE

Part III incorporates by reference certain information to be contained in the Company’s definitive proxy statement, which the Company anticipates will be filed no later than April 15, 2010, and thus these items have been omitted in accordance with General Instruction G(3) to Form 10-K.

2

Table of Contents

EQUITY RESIDENTIAL

TABLE OF CONTENTS

3

Table of Contents

General

Equity Residential (“EQR”), a Maryland real estate investment trust (“REIT”) formed in March 1993, is an S&P 500 company focused on the acquisition, development and management of high quality apartment properties in top United States growth markets. EQR has elected to be taxed as a REIT.

The Company is one of the largest publicly traded real estate companies and is the largest publicly traded owner of multifamily properties in the United States (based on the aggregate market value of its outstanding Common Shares, the number of apartment units wholly owned and total revenues earned). The Company’s corporate headquarters are located in Chicago, Illinois and the Company also operates property management offices throughout the United States.

EQR is the general partner of, and as of December 31, 2009 owned an approximate 95.2% ownership interest in, ERP Operating Limited Partnership, an Illinois limited partnership (the “Operating Partnership”). The Company is structured as an umbrella partnership REIT (“UPREIT”) under which all property ownership and related business operations are conducted through the Operating Partnership and its subsidiaries. References to the “Company” include EQR, the Operating Partnership and those entities owned or controlled by the Operating Partnership and/or EQR.

As of December 31, 2009, the Company, directly or indirectly through investments in title holding entities, owned all or a portion of 495 properties in 23 states and the District of Columbia consisting of 137,007 units. The ownership breakdown includes (table does not include various uncompleted development properties):

As of December 31, 2009, the Company has approximately 4,100 employees who provide real estate operations, leasing, legal, financial, accounting, acquisition, disposition, development and other support functions.

Certain capitalized terms used herein are defined in the Notes to Consolidated Financial Statements.

Available Information

You may access our Annual Report on Form 10-K, our Quarterly Reports on Form 10-Q, our Current Reports on Form 8-K and any amendments to any of those reports we file with the SEC free of charge at our website, www.equityresidential.com . These reports are made available at our website as soon as reasonably practicable after we file them with the SEC.

Business Objectives and Operating Strategies

The Company seeks to maximize current income, capital appreciation of each property and the total return for its shareholders. The Company’s strategy for accomplishing these objectives includes:

4

Table of Contents

Acquisition, Development and Disposition Strategies

The Company anticipates that future property acquisitions, developments and dispositions will occur within the United States. Acquisitions and developments may be financed from various sources of capital, which may include retained cash flow, issuance of additional equity and debt securities, sales of properties, joint venture agreements and collateralized and uncollateralized borrowings. In addition, the Company may acquire properties in transactions that include the issuance of limited partnership interests in the Operating Partnership (“OP Units”) as consideration for the acquired properties. Such transactions may, in certain circumstances, enable the sellers to defer, in whole or in part, the recognition of taxable income or gain that might otherwise result from the sales. EQR may also acquire land parcels to hold and/or sell based on market opportunities.

When evaluating potential acquisitions, developments and dispositions, the Company generally considers the following factors:

The Company generally reinvests the proceeds received from property dispositions primarily to achieve its acquisition, development and rehab strategies and at times to fund its debt and equity repurchase activities. In addition, when feasible, the Company may structure these transactions as tax-deferred exchanges.

See also Note 20 in the Notes to Consolidated Financial Statements for additional discussion regarding the Company’s segment disclosures.

5

Table of Contents

Please refer to Item 7, Management’s Discussion and Analysis of Financial Condition and Results of Operations , for the Company’s Capital Structure chart as of December 31, 2009.

Major Debt and Equity Activities for the Years Ended December 31, 2009, 2008 and 2007

During 2009:

During 2008:

6

Table of Contents

During 2007:

During the first quarter of 2010 through February 19, 2010, the Company has issued approximately 1.1 million Common Shares at an average price of $33.87 per share for total consideration of approximately $35.8 million through the ATM share offering program.

As of the date of this filing, an unlimited amount of debt securities remains available for issuance by the Operating Partnership under a registration statement that became automatically effective upon filing with the SEC in December 2008 (under SEC regulations enacted in 2005, the registration statement automatically expires on December 21, 2011 and does not contain a maximum issuance amount). As of the date of this filing, an unlimited amount of equity securities remains available for issuance by the Company under a registration statement the SEC declared effective in December 2008 (under SEC regulations enacted in 2005, the registration statement automatically expires on December 15, 2011 and does not contain a maximum issuance amount).

In May 2002, the Company’s shareholders approved the Company’s 2002 Share Incentive Plan. In January 2003, the Company filed a Form S-8 registration statement to register 23,125,828 Common Shares under this plan. As of January 1, 2010, 22,091,629 shares are the maximum shares issuable under this plan. See Note 14 in the Notes to Consolidated Financial Statements for further discussion.

Credit Facilities

The Operating Partnership has a $1.5 billion unsecured revolving credit facility maturing on February 28, 2012, with the ability to increase available borrowings by an additional $500.0 million by adding additional banks to the facility or obtaining the agreement of existing banks to increase their commitments. Advances under the credit facility bear interest at variable rates based upon LIBOR at various interest periods plus a spread (currently 0.5%) dependent upon the Operating Partnership’s credit rating or based on bids received from the lending group. EQR has guaranteed the Operating Partnership’s credit facility up to the maximum amount and for the full term of the facility.

During the year ended December 31, 2008, one of the providers of the Operating Partnership’s unsecured revolving credit facility declared bankruptcy. Under the existing terms of the credit facility, the provider’s share is up to $75.0 million of potential borrowings. As a result, the Operating Partnership’s borrowing capacity under the unsecured revolving credit facility has, in essence, been permanently reduced to $1.425 billion of potential borrowings. The obligation to fund by all of the other providers has not changed.

7

Table of Contents

As of December 31, 2009, the amount available on the credit facility was $1.37 billion (net of $56.7 million which was restricted/dedicated to support letters of credit and net of the $75.0 million discussed above). As of December 31, 2008, the amount available on the credit facility was $1.29 billion (net of $130.0 million which was restricted/dedicated to support letters of credit and net of the $75.0 million discussed above). The Company did not draw on its revolving credit facility and had no balance outstanding at any time during the year ended December 31, 2009. During the year ended December 31, 2008, the weighted average interest rate was 4.31%.

Competition

All of the Company’s properties are located in developed areas that include other multifamily properties. The number of competitive multifamily properties in a particular area could have a material effect on the Company’s ability to lease units at the properties or at any newly acquired properties and on the rents charged. The Company may be competing with other entities that have greater resources than the Company and whose managers have more experience than the Company’s managers. In addition, other forms of rental properties and single family housing provide housing alternatives to potential residents of multifamily properties. See Item 1A. Risk Factors for additional information with respect to competition.

Environmental Considerations

See Item 1A. Risk Factors for information concerning the potential effects of environmental regulations on our operations.

General

The following Risk Factors may contain defined terms that are different from those used in the other sections of this report. Unless otherwise indicated, when used in this section, the terms “we” and “us” refer to Equity Residential and its subsidiaries, including ERP Operating Limited Partnership. This Item 1A. includes forward-looking statements. You should refer to our discussion of the qualifications and limitations on forward-looking statements included in Item 7.

The occurrence of the events discussed in the following risk factors could adversely affect, possibly in a material manner, our business, financial condition or results of operations, which could adversely affect the value of our common shares of beneficial interest or preferred shares of beneficial interest (which we refer to collectively as “Shares”) and limited partnership interests in the Operating Partnership (“OP Units”). In this section, we refer to the Shares and the OP Units together as our “securities” and the investors who own Shares and/or OP Units as our “security holders”.

Our Performance and Securities Value are Subject to Risks Associated with the Real Estate Industry

General

Real property investments are subject to varying degrees of risk and are relatively illiquid. Several factors may adversely affect the economic performance and value of our properties. These factors include changes in the national, regional and local economic climates, local conditions such as an oversupply of multifamily properties or a reduction in demand for our multifamily properties, the attractiveness of our properties to residents, competition from other available multifamily property owners and single family homes and changes in market rental rates. Our performance also depends on our ability to collect rent from residents and to pay for adequate maintenance, insurance and other operating costs, including real estate taxes, which could increase over time. Sources of labor and materials required for maintenance, repair, capital expenditure or development may be more expensive than anticipated. Also, the expenses of owning and operating a property are not necessarily reduced when circumstances such as market factors and competition cause a reduction in income from the property.

We May Not Have Sufficient Cash Flows From Operations After Capital Expenditures to Cover Our Distributions

We generally consider our cash flows provided by operating activities after capital expenditures to be adequate to meet operating requirements and payment of distributions to our security holders. However, there may be times when we experience shortfalls in our coverage of distributions, which may cause us to consider reducing our distributions and/or using the proceeds from property dispositions or additional financing transactions to make up the

8

Table of Contents

difference. Should these shortfalls occur for lengthy periods of time or be material in nature, our financial condition may be adversely affected and we may not be able to maintain our current distribution levels.

We May Be Unable to Renew Leases or Relet Units as Leases Expire

When our residents decide not to renew their leases upon expiration, we may not be able to relet their units. Even if the residents do renew or we can relet the units, the terms of renewal or reletting may be less favorable than current lease terms. Because virtually all of our leases are for apartments, they are generally for terms of no more than one year. If we are unable to promptly renew the leases or relet the units, or if the rental rates upon renewal or reletting are significantly lower than expected rates, then our results of operations and financial condition will be adversely affected. Occupancy levels and market rents may be adversely affected by national and local economic and market conditions including, without limitation, new construction and excess inventory of multifamily and single family housing, slow or negative employment growth, availability of low interest mortgages for single family home buyers and the potential for geopolitical instability, all of which are beyond the Company’s control. In addition, various state and local municipalities are considering and may continue to consider rent control legislation which could limit our ability to raise rents. Finally, the federal government is considering and may continue to consider policies which may encourage home ownership, thus increasing competition and possibly limiting our ability to raise rents. Consequently, our cash flow and ability to service debt and make distributions to security holders could be reduced.

New Acquisitions and/or Development Projects May Fail to Perform as Expected and Competition for Acquisitions May Result in Increased Prices for Properties

We intend to actively acquire multifamily properties for rental operations as market conditions dictate. The Company also develops projects and currently has several properties under development. We may begin new development activities if conditions warrant. We may underestimate the costs necessary to bring an acquired property up to standards established for its intended market position or to complete a development property. Additionally, we expect that other major real estate investors with significant capital will compete with us for attractive investment opportunities or may also develop properties in markets where we focus our development efforts. This competition may increase prices for multifamily properties. We may not be in a position or have the opportunity in the future to make suitable property acquisitions on favorable terms. To the extent that we do develop more properties if conditions warrant, we expect to do so ourselves in addition to co-investing with our development partners. The total number of development units, costs of development and estimated completion dates are subject to uncertainties arising from changing economic conditions (such as the cost of labor and construction materials), competition and local government regulation.

In connection with such government regulation, we may incur liability if our properties are not constructed and operated in compliance with the accessibility provisions of the Americans with Disabilities Acts, the Fair Housing Act or other federal, state or local requirements. Noncompliance could result in fines, subject us to lawsuits and require us to remediate or repair the noncompliance.

Because Real Estate Investments Are Illiquid, We May Not Be Able to Sell Properties When Appropriate

Real estate investments generally cannot be sold quickly. We may not be able to reconfigure our portfolio promptly in response to economic or other conditions. This inability to respond promptly to changes in the performance of our investments could adversely affect our financial condition and ability to make distributions to our security holders.

The Value of Investment Securities Could Result In Losses to the Company

From time to time, the Company holds investment securities that have a higher risk profile than the government obligations and bond funds, money market funds or bank deposits in which we generally invest. On occasion we may purchase securities of companies in our own industry as a means to invest funds. There may be times when we experience declines in the value of these investment securities, which may result in losses to the Company and our financial condition or results of operations could be adversely affected. Sometimes the cash we deposit at a bank exceeds the FDIC insurance limit resulting in risk to the Company of loss of funds if these banks fail.

Changes in Laws and Litigation Risk Could Affect Our Business

We are generally not able to pass through to our residents under existing leases real estate or other federal, state or local taxes. Consequently, any such tax increases may adversely affect our financial condition and limit our ability to make distributions to our security holders.

We may become involved in legal proceedings, including but not limited to, proceedings related to consumer, employment, development, condominium conversion, tort and commercial legal issues that if decided adversely to or settled by us, could result in liability material to our financial condition or results of operations.

9

Table of Contents

Environmental Problems Are Possible and Can Be Costly

Federal, state and local laws and regulations relating to the protection of the environment may require a current or previous owner or operator of real estate to investigate and clean up hazardous or toxic substances or petroleum product releases at such property. The owner or operator may have to pay a governmental entity or third parties for property damage and for investigation and clean-up costs incurred by such parties in connection with the contamination. These laws typically impose clean-up responsibility and liability without regard to whether the owner or operator knew of or caused the presence of the contaminants. Even if more than one person may have been responsible for the contamination, each person covered by the environmental laws may be held responsible for all of the clean-up costs incurred. In addition, third parties may sue the owner or operator of a site for damages and costs resulting from environmental contamination emanating from that site.

Substantially all of our properties have been the subject of environmental assessments completed by qualified independent environmental consulting companies. While these environmental assessments have not revealed, nor are we aware of, any environmental liability that our management believes would have a material adverse effect on our business, results of operations, financial condition or liquidity, there can be no assurance that we will not incur such liabilities in the future.

Over the past several years, there have been an increasing number of lawsuits against owners and managers of multifamily properties alleging personal injury and property damage caused by the presence of mold in residential real estate. As some of these lawsuits have resulted in substantial monetary judgments or settlements, insurance carriers have reacted by excluding mold-related claims from standard policies and pricing mold endorsements at prohibitively high rates. We have adopted programs designed to minimize the existence of mold in any of our properties as well as guidelines for promptly addressing and resolving reports of mold to minimize any impact mold might have on our residents or the property.

We cannot be assured that existing environmental assessments of our properties reveal all environmental liabilities, that any prior owner of any of our properties did not create a material environmental condition not known to us, or that a material environmental condition does not otherwise exist as to any of our properties.

Climate Change

To the extent that climate change does occur, we may experience extreme weather and changes in precipitation and temperature, all of which may result in physical damage or a decrease in demand for properties located in these areas or affected by these conditions. Should the impact of climate change be material in nature, including destruction of our properties, or occur for lengthy periods of time, our financial condition or results of operations may be adversely affected.

In addition, developments in federal and state legislation and regulation on climate change could result in increased capital expenditures to improve the energy efficiency of our existing properties and could also require us to spend more on our new development properties without a corresponding increase in revenue.

Insurance Policy Deductibles and Exclusions

In order to manage insurance costs, management has gradually increased deductible and self-insured retention amounts. As of December 31, 2009, the Company’s property insurance policy provides for a per occurrence deductible of $250,000 and self-insured retention of $5.0 million per occurrence, subject to a maximum annual aggregate self-insured retention of $7.5 million, with approximately 80% of any excess losses being covered by insurance. Any earthquake and named windstorm losses are subject to a deductible of 5% of the values of the buildings involved in the losses and are not subject to the aggregate self-insured retention. The Company’s general liability and worker’s compensation policies at December 31, 2009 provide for a $2.0 million and $1.0 million per occurrence deductible, respectively. These higher deductible and self-insured retention amounts do expose the Company to greater potential uninsured losses, but management believes the savings in insurance premium expense justify this potential increased exposure over the long-term. However, the potential impact of climate change and increased severe weather could cause a significant increase in insurance premiums and deductibles, particularly for our coastal properties, or a decrease in the availability of coverage, either of which could expose the Company to even greater uninsured losses which may adversely affect our financial condition or results of operations.

As a result of the terrorist attacks of September 11, 2001, property insurance carriers created exclusions for losses from terrorism from our “all risk” property insurance policies. As of December 31, 2009, the Company was

10

Table of Contents

insured for $500.0 million in terrorism insurance coverage, with a $100,000 deductible. This coverage excludes losses from nuclear, biological and chemical attacks. In the event of a terrorist attack impacting one or more of our properties, we could lose the revenues from the property, our capital investment in the property and possibly face liability claims from residents or others suffering injuries or losses. The Company believes, however, that the number of properties in and geographic diversity of its portfolio and its terrorism insurance coverage help to mitigate its exposure to the risks associated with potential terrorist attacks.

Debt Financing and Preferred Shares Could Adversely Affect Our Performance

General

Please refer to Item 7, Management’s Discussion and Analysis of Financial Condition and Results of Operations , for the Company’s total debt and unsecured debt summaries as of December 31, 2009.

In addition to debt, we have $208.8 million of combined liquidation value of outstanding preferred shares of beneficial interest with a weighted average dividend preference of 6.94% per annum as of December 31, 2009. Our use of debt and preferred equity financing creates certain risks, including the following:

Disruptions in the Financial Markets Could Adversely Affect Our Ability to Obtain Debt Financing and Impact our Acquisitions and Dispositions

Dislocations and liquidity disruptions in capital and credit markets could impact liquidity in the debt markets, resulting in financing terms that are less attractive to us and/or the unavailability of certain types of debt financing. Should the capital and credit markets experience volatility and the availability of funds again become limited, or be available only on unattractive terms, we will incur increased costs associated with issuing debt instruments. In addition, it is possible that our ability to access the capital and credit markets may be limited or precluded by these or other factors at a time when we would like, or need, to do so, which would adversely impact our ability to refinance maturing debt and/or react to changing economic and business conditions. Disruptions in the floating rate tax-exempt bond market (where interest rates reset weekly) and in the credit market’s perception of Fannie Mae and Freddie Mac, which guarantee and provide liquidity for these bonds, have been experienced in the past and may be experienced in the future and could result in an increase in interest rates on these debt obligations. These bonds could also be put to our consolidated subsidiaries if Fannie Mae or Freddie Mac fail to satisfy their guaranty obligations. While this obligation is in almost all cases non-recourse to us, this could cause the Company to have to repay these obligations on short notice or risk foreclosure actions on the collateralized assets. Furthermore, while we believe Fannie Mae and Freddie Mac will continue to provide liquidity to our sector, should they discontinue doing so, have their mandates changed or reduced or be disbanded or reorganized by the government, it would significantly reduce our access to debt capital and/or increase borrowing costs and would significantly reduce our sales of assets. Uncertainty in the credit markets could negatively impact our ability to make acquisitions and make it more difficult or not possible for us to sell properties or may adversely affect the price we receive for properties that we do sell, as prospective buyers may experience increased costs of debt financing or difficulties in obtaining debt financing. Potential continued disruptions in the financial markets could also have other unknown adverse effects on us or the economy generally and may cause the price of our Common Shares to fluctuate significantly and/or to decline.

Non-Performance by Our Counterparties Could Adversely Affect Our Performance

Although we have not experienced any material counterparty non-performance, disruptions in financial and credit markets could, among other things, impede the ability of our counterparties to perform on their contractual obligations. There are multiple financial institutions that are individually committed to lend us varying amounts as part of our revolving credit facility. Should any of these institutions fail to fund their committed amounts when contractually required, our financial condition could be adversely affected. Should several of these institutions fail to fund, we could experience significant financial distress. One of the financial institutions, with a commitment of $75.0 million, declared bankruptcy in 2008 and it is unlikely that they will honor their financial commitment. Our borrowing capacity under the credit facility has in essence been permanently reduced to $1.425 billion.

The Company also has several assets under development with joint venture partners which were financed by financial institutions that have experienced varying degrees of distress in the past and could experience similar distress as economic conditions change. If one or more of these lenders fail to fund when contractually required, the Company or its joint venture partner may be unable to complete construction of its development properties. Further, the Company’s joint venture partners may experience financial distress and to the extent they do not meet their obligations to us or our joint ventures with them, we may be adversely affected. In addition, the Company relies on third party insurance providers for its property, general liability and worker’s compensation insurance. While there has yet to be any non-performance by these major

11

Table of Contents

insurance providers, should any of them experience liquidity issues or other financial distress, it could negatively impact the Company.

A Significant Downgrade in Our Credit Ratings Could Adversely Affect Our Performance

A significant downgrade in our credit ratings, while not affecting our ability to draw proceeds under the revolving credit facility, would cause our borrowing costs to increase under the facility and impact our ability to borrow secured and unsecured debt by increasing borrowing costs, or otherwise limit our access to capital. In addition, a downgrade below investment grade would require us to post cash collateral and/or letters of credit in favor of some of our secured lenders to cover our self-insured property and liability insurance deductibles.

Scheduled Debt Payments Could Adversely Affect Our Financial Condition

In the future, our cash flow could be insufficient to meet required payments of principal and interest or to pay distributions on our securities at expected levels.

We may not be able to refinance existing debt, including joint venture indebtedness (which in virtually all cases requires substantial principal payments at maturity) and, if we can, the terms of such refinancing might not be as favorable as the terms of existing indebtedness. If principal payments due at maturity cannot be refinanced, extended or paid with proceeds of other capital transactions, such as new equity capital, our cash flow will not be sufficient in all years to repay all maturing debt. As a result, certain of our other debt may cross default, we may be forced to postpone capital expenditures necessary for the maintenance of our properties, we may have to dispose of one or more properties on terms that would otherwise be unacceptable to us or we may be forced to allow the mortgage holder to foreclose on a property.

If a property we own is mortgaged to secure debt and we are unable to meet the mortgage payments, the holder of the mortgage could foreclose on the property, resulting in loss of income and asset value. Foreclosure on mortgaged properties or an inability to refinance existing indebtedness would likely have a negative impact on our financial condition and results of operations.

Please refer to Item 7, Management’s Discussion and Analysis of Financial Condition and Results of Operations , for the Company’s debt maturity schedule as of December 31, 2009.

Financial Covenants Could Adversely Affect the Company’s Financial Condition

The mortgages on our properties may contain customary negative covenants that, among other things, limit our ability, without the prior consent of the lender, to further mortgage the property and to reduce or change insurance coverage. In addition, our unsecured credit facilities contain certain restrictions, requirements and other limitations on our ability to incur debt. The indentures under which a substantial portion of our unsecured debt was issued also contain certain financial and operating covenants including, among other things, maintenance of certain financial ratios, as well as limitations on our ability to incur secured and unsecured debt (including acquisition financing), and to sell all or substantially all of our assets. Our credit facilities and indentures are cross-defaulted and also contain cross default provisions with other material debt. The Company believes it was in compliance with its unsecured public debt covenants for both the years ended December 31, 2009 and 2008.

Some of the properties were financed with tax-exempt bonds that contain certain restrictive covenants or deed restrictions. We have retained an independent outside consultant to monitor compliance with the restrictive covenants and deed restrictions that affect these properties. If these bond compliance requirements restrict our ability to increase our rental rates to low or moderate-income residents, or eligible/qualified residents, then our income from these properties may be limited. Generally, we believe that the interest rate benefit attendant to properties with tax-exempt bonds more than outweighs any loss of income due to restrictive covenants or deed restrictions.

Our Degree of Leverage Could Limit Our Ability to Obtain Additional Financing

Our consolidated debt-to-total market capitalization ratio was 48.1% as of December 31, 2009. Our degree of leverage could have important consequences to security holders. For example, the degree of leverage could affect our ability to obtain additional financing in the future for working capital, capital expenditures, acquisitions, development or other general corporate purposes, making us more vulnerable to a downturn in business or the economy in general.

12

Table of Contents

Rising Interest Rates Could Adversely Affect Cash Flow

Advances under our credit facilities bear interest at variable rates based upon LIBOR at various interest periods, plus a spread dependent upon the Operating Partnership’s credit rating, or based upon bids received from the lending group. Certain public issuances of our senior unsecured debt instruments may also, from time to time, bear interest at floating rates. We may also borrow additional money with variable interest rates in the future. Increases in interest rates would increase our interest expense under these debt instruments and would increase the costs of refinancing existing debt and of issuing new debt. Accordingly, higher interest rates could adversely affect cash flow and our ability to service our debt and make distributions to security holders.

Derivatives and Hedging Activity Could Adversely Affect Cash Flow

In the normal course of business, we use derivatives to hedge our exposure to interest rate volatility on debt instruments, including hedging for future debt issuances. There can be no assurance that these hedging arrangements will have the desired beneficial impact. These arrangements, which can include a number of counterparties, may expose us to additional risks, including failure of any of our counterparties to perform under these contracts, and may involve extensive costs, such as transaction fees or breakage costs, if we terminate them. No strategy can completely insulate us from the risks associated with interest rate fluctuations.

We Depend on Our Key Personnel

We depend on the efforts of the Chairman of our Board of Trustees, Samuel Zell, and our executive officers, particularly David J. Neithercut, our President and Chief Executive Officer (“CEO”). If they resign or otherwise cease to be employed by us, our operations could be temporarily adversely affected. Mr. Zell has entered into retirement benefit and noncompetition agreements with the Company.

Control and Influence by Significant Shareholders Could Be Exercised in a Manner Adverse to Other Shareholders

The consent of certain affiliates of Mr. Zell is required for certain amendments to the Sixth Amended and Restated Agreement of Limited Partnership of the Operating Partnership (the “Partnership Agreement”). As a result of their security ownership and rights concerning amendments to the Partnership Agreement, the security holders referred to herein may have influence over the Company. Although to the Company’s knowledge these security holders have not agreed to act together on any matter, they would be in a position to exercise even more influence over the Company’s affairs if they were to act together in the future. This influence could conceivably be exercised in a manner that is inconsistent with the interests of other security holders. For additional information regarding the security ownership of our trustees, including Mr. Zell, and our executive officers, see the Company’s definitive proxy statement.

Shareholders’ Ability to Effect Changes in Control of the Company is Limited

Provisions of Our Declaration of Trust and Bylaws Could Inhibit Changes in Control

Certain provisions of our Declaration of Trust and Bylaws may delay or prevent a change in control of the Company or other transactions that could provide the security holders with a premium over the then-prevailing market price of their securities or which might otherwise be in the best interest of our security holders. This includes the 5% Ownership Limit described below. While our existing preferred shares do not have these provisions, any future series of preferred shares may have certain voting provisions that could delay or prevent a change in control or other transactions that might otherwise be in the interest of our security holders. In 2008, we adopted amendments to our Bylaws to expand the information required to be provided by any security holder, or persons acting in concert with such security holder, who proposes business or a nominee at an annual meeting of shareholders, including disclosure of information related to hedging activities and investment strategies with respect to our securities. These amendments could delay or prevent a change in control or other transactions that might otherwise be in the interest of our security holders.

We Have a Share Ownership Limit for REIT Tax Purposes

To remain qualified as a REIT for federal income tax purposes, not more than 50% in value of our outstanding Shares may be owned, directly or indirectly, by five or fewer individuals at any time during the last half of any year. To facilitate maintenance of our REIT qualification, our Declaration of Trust, subject to certain exceptions, prohibits ownership by any single shareholder of more than 5% of the lesser of the number or value of the outstanding

13

Table of Contents

class of common or preferred shares. We refer to this restriction as the “Ownership Limit.” Absent any exemption or waiver granted by our Board of Trustees, securities acquired or held in violation of the Ownership Limit will be transferred to a trust for the exclusive benefit of a designated charitable beneficiary, and the security holder’s rights to distributions and to vote would terminate. A transfer of Shares may be void if it causes a person to violate the Ownership Limit. The Ownership Limit could delay or prevent a change in control and, therefore, could adversely affect our security holders’ ability to realize a premium over the then-prevailing market price for their Shares. To reduce the ability of the Board to use the Ownership Limit as an anti-takeover device, in 2004 the Company amended the Ownership Limit to require, rather than permit, the Board to grant a waiver of the Ownership Limit if the individual seeking a waiver demonstrates that such ownership would not jeopardize the Company’s status as a REIT.

Our Preferred Shares May Affect Changes in Control

Our Declaration of Trust authorizes the Board of Trustees to issue up to 100 million preferred shares, and to establish the preferences and rights (including the right to vote and the right to convert into common shares) of any preferred shares issued. The Board of Trustees may use its powers to issue preferred shares and to set the terms of such securities to delay or prevent a change in control of the Company, even if a change in control were in the interest of security holders.

Inapplicability of Maryland Law Limiting Certain Changes in Control

Certain provisions of Maryland law applicable to real estate investment trusts prohibit “business combinations” (including certain issuances of equity securities) with any person who beneficially owns ten percent or more of the voting power of outstanding securities, or with an affiliate who, at any time within the two-year period prior to the date in question, was the beneficial owner of ten percent or more of the voting power of the Company’s outstanding voting securities (an “Interested Shareholder”), or with an affiliate of an Interested Shareholder. These prohibitions last for five years after the most recent date on which the Interested Shareholder became an Interested Shareholder. After the five-year period, a business combination with an Interested Shareholder must be approved by two super-majority shareholder votes unless, among other conditions, holders of common shares receive a minimum price for their shares and the consideration is received in cash or in the same form as previously paid by the Interested Shareholder for its common shares. As permitted by Maryland law, however, the Board of Trustees of the Company has opted out of these restrictions with respect to any business combination involving Mr. Zell and certain of his affiliates and persons acting in concert with them. Consequently, the five-year prohibition and the super-majority vote requirements will not apply to a business combination involving us and/or any of them. Such business combinations may not be in the best interest of our security holders.

Our Success as a REIT Is Dependent on Compliance with Federal Income Tax Requirements

Our Failure to Qualify as a REIT Would Have Serious Adverse Consequences to Our Security Holders

We believe that we have qualified for taxation as a REIT for federal income tax purposes since our taxable year ended December 31, 1992 based, in part, upon opinions of tax counsel received whenever we have issued equity securities or engaged in significant merger transactions. We plan to continue to meet the requirements for taxation as a REIT. Many of these requirements, however, are highly technical and complex. We cannot, therefore, guarantee that we have qualified or will qualify in the future as a REIT. The determination that we are a REIT requires an analysis of various factual matters that may not be totally within our control. For example, to qualify as a REIT, our gross income must generally come from rental and other real estate or passive related sources that are itemized in the REIT tax laws. We are also required to distribute to security holders at least 90% of our REIT taxable income excluding capital gains. The fact that we hold our assets through ERP Operating Limited Partnership and its subsidiaries further complicates the application of the REIT requirements. Even a technical or inadvertent mistake could jeopardize our REIT status. Furthermore, Congress and the IRS might make changes to the tax laws and regulations, and the courts might issue new rulings that make it more difficult, or impossible, for us to remain qualified as a REIT. We do not believe, however, that any pending or proposed tax law changes would jeopardize our REIT status. In addition, Congress and the IRS have recently liberalized the REIT qualification rules to permit REITs in certain circumstances to pay a monetary penalty for inadvertent mistakes rather than lose REIT status.

If we fail to qualify as a REIT, we would be subject to federal income tax at regular corporate rates. Also, unless the IRS granted us relief under certain statutory provisions, we would remain disqualified from taxation as a REIT for four years following the year in which we failed to qualify as a REIT. If we fail to qualify as a REIT, we would have to pay significant income taxes. We, therefore, would have less money available for investments or for distributions to security holders. This would likely have a significant adverse effect on the value of our securities. In

14

Table of Contents

addition, we would no longer be required to make any distributions to security holders. Even if we qualify as a REIT, we are and will continue to be subject to certain federal, state and local taxes on our income and property. In addition, our corporate housing business and condominium conversion business, which are conducted through taxable REIT subsidiaries, generally will be subject to federal and state income tax at regular corporate rates to the extent they have taxable income.

We Could Be Disqualified as a REIT or Have to Pay Taxes if Our Merger Partners Did Not Qualify as REITs

If any of our prior merger partners had failed to qualify as a REIT throughout the duration of their existence, then they might have had undistributed “C corporation earnings and profits” at the time of their merger with us. If that was the case and we did not distribute those earnings and profits prior to the end of the year in which the merger took place, we might not qualify as a REIT. We believe based, in part, upon opinions of legal counsel received pursuant to the terms of our merger agreements as well as our own investigations, among other things, that each of our prior merger partners qualified as a REIT and that, in any event, none of them had any undistributed “C corporation earnings and profits” at the time of their merger with us. If any of our prior merger partners failed to qualify as a REIT, an additional concern would be that they could have been required to recognize taxable gain at the time they merged with us. We would be liable for the tax on such gain. We also could have to pay corporate income tax on any gain existing at the time of the applicable merger on assets acquired in the merger if the assets are sold within ten years of the merger.

Compliance with REIT Distribution Requirements May Affect Our Financial Condition

Distribution Requirements May Increase the Indebtedness of the Company

We may be required from time to time, under certain circumstances, to accrue as income for tax purposes interest and rent earned but not yet received. In such event, or upon our repayment of principal on debt, we could have taxable income without sufficient cash to enable us to meet the distribution requirements of a REIT. Accordingly, we could be required to borrow funds or liquidate investments on adverse terms in order to meet these distribution requirements.

Tax Elections Regarding Distributions May Impact Future Liquidity of the Company

During 2008 and 2009, we did make, and under certain circumstances may consider making again in the future, a tax election to treat future distributions to shareholders as distributions in the current year. This election, which is provided for in the REIT tax code, may allow us to avoid increasing our dividends or paying additional income taxes in the current year. However, this could result in a constraint on our ability to decrease our dividends in future years without creating risk of either violating the REIT distribution requirements or generating additional income tax liability.

Federal Income Tax Considerations

General

The following discussion summarizes the federal income tax considerations material to a holder of common shares. It is not exhaustive of all possible tax considerations. For example, it does not give a detailed discussion of any state, local or foreign tax considerations. The following discussion also does not address all tax matters that may be relevant to prospective shareholders in light of their particular circumstances. Moreover, it does not address all tax matters that may be relevant to shareholders who are subject to special treatment under the tax laws, such as insurance companies, tax-exempt entities, financial institutions or broker-dealers, foreign corporations, persons who are not citizens or residents of the United States and persons who own shares through a partnership or other entity treated as a flow-through entity for federal income tax purposes.

The specific tax attributes of a particular shareholder could have a material impact on the tax considerations associated with the purchase, ownership and disposition of common shares. Therefore, it is essential that each prospective shareholder consult with his or her own tax advisors with regard to the application of the federal income tax laws to the shareholder’s personal tax situation, as well as any tax consequences arising under the laws of any state, local or foreign taxing jurisdiction.

The information in this section is based on the current Internal Revenue Code, current, temporary and proposed Treasury regulations, the legislative history of the Internal Revenue Code, current administrative

15

Table of Contents

interpretations and practices of the Internal Revenue Service, including its practices and policies as set forth in private letter rulings, which are not binding on the Internal Revenue Service, and existing court decisions. Future legislation, regulations, administrative interpretations and court decisions could change current law or adversely affect existing interpretations of current law. Any change could apply retroactively. Thus, it is possible that the Internal Revenue Service could challenge the statements in this discussion, which do not bind the Internal Revenue Service or the courts, and that a court could agree with the Internal Revenue Service.

Our Taxation

We elected REIT status beginning with the year that ended December 31, 1992. In any year in which we qualify as a REIT, we generally will not be subject to federal income tax on the portion of our REIT taxable income or capital gain that we distribute to our shareholders. This treatment substantially eliminates the double taxation that applies to most corporations, which pay a tax on their income and then distribute dividends to shareholders who are in turn taxed on the amount they receive. We elected taxable REIT subsidiary status for certain of our corporate subsidiaries, primarily those engaged in condominium conversion and sale activities. As a result, we will be subject to federal income taxes for activities performed by our taxable REIT subsidiaries.

We will be subject to federal income tax at regular corporate rates upon our REIT taxable income or capital gains that we do not distribute to our shareholders. In addition, we will be subject to a 4% excise tax if we do not satisfy specific REIT distribution requirements. We could also be subject to the “alternative minimum tax” on our items of tax preference. In addition, any net income from “prohibited transactions” (i.e., dispositions of property, other than property held by a taxable REIT subsidiary, held primarily for sale to customers in the ordinary course of business) will be subject to a 100% tax. We could also be subject to a 100% penalty tax on certain payments received from or on certain expenses deducted by a taxable REIT subsidiary if any such transaction is not respected by the Internal Revenue Service. If we fail to satisfy the 75% gross income test or the 95% gross income test (described below) but have maintained our qualification as a REIT because we satisfied certain other requirements, we will still generally be subject to a 100% penalty tax on the taxable income attributable to the gross income that caused the income test failure. If we fail to satisfy any of the REIT asset tests (described below) by more than a de minimis amount, due to reasonable cause, and we nonetheless maintain our REIT qualification because of specified cure provisions, we will be required to pay a tax equal to the greater of $50,000 or the highest marginal corporate tax rate multiplied by the net income generated by the non-qualifying assets. If we fail to satisfy any provision of the Internal Revenue Code that would result in our failure to qualify as a REIT (other than a violation of the REIT gross income or asset tests described below) and the violation is due to reasonable cause, we may retain our REIT qualification but we will be required to pay a penalty of $50,000 for each such failure. Moreover, we may be subject to taxes in certain situations and on certain transactions that we do not presently contemplate.

We believe that we have qualified as a REIT for all of our taxable years beginning with 1992. We also believe that our current structure and method of operation is such that we will continue to qualify as a REIT. However, given the complexity of the REIT qualification requirements, we cannot provide any assurance that the actual results of our operations have satisfied or will satisfy the requirements under the Internal Revenue Code for a particular year.

If we fail to qualify for taxation as a REIT in any taxable year and the relief provisions described herein do not apply, we will be subject to tax on our taxable income at regular corporate rates. We also may be subject to the corporate “alternative minimum tax.” As a result, our failure to qualify as a REIT would significantly reduce the cash we have available to distribute to our shareholders. Unless entitled to statutory relief, we would not be able to re-elect to be taxed as a REIT until our fifth taxable year after the year of disqualification. It is not possible to state whether we would be entitled to statutory relief.

Our qualification and taxation as a REIT depend on our ability to satisfy various requirements under the Internal Revenue Code. We are required to satisfy these requirements on a continuing basis through actual annual operating and other results. Accordingly, there can be no assurance that we will be able to continue to operate in a manner so as to remain qualified as a REIT.

Ownership of Taxable REIT Subsidiaries by Us . The Internal Revenue Code provides that REITs may own greater than ten percent of the voting power and value of the securities of “taxable REIT subsidiaries” or “TRSs”, which are corporations subject to tax as a regular “C” corporation that have elected, jointly with a REIT, to be a TRS. Generally, a taxable REIT subsidiary may own assets that cannot otherwise be owned by a REIT and can perform impermissible tenant services (discussed below), which would otherwise taint our rental income under the REIT income tests. However, the REIT will be obligated to pay a 100% penalty tax on some payments that we receive or on certain expenses deducted by our TRSs if the economic arrangements between us, our tenants and the TRS are not

16

Table of Contents

comparable to similar arrangements among unrelated parties. A TRS may also receive income from prohibited transactions without incurring the 100% federal income tax liability imposed on REITs. Income from prohibited transactions may include the purchase and sale of land, the purchase and sale of completed development properties and the sale of condominium units.

TRSs pay federal and state income tax at the full applicable corporate rates. The amount of taxes paid on impermissible tenant services income and the sale of real estate held primarily for sale to customers in the ordinary course of business may be material in amount. The TRSs will attempt to reduce, if possible, the amount of these taxes, but we cannot guarantee whether, or the extent to which, measures taken to reduce these taxes will be successful. To the extent that these companies are required to pay taxes, less cash may be available for distributions to shareholders.

Share Ownership Test and Organizational Requirement . In order to qualify as a REIT, our shares of beneficial interest must be held by a minimum of 100 persons for at least 335 days of a taxable year that is 12 months, or during a proportionate part of a taxable year of less than 12 months. Also, not more than 50% in value of our shares of beneficial interest may be owned directly or indirectly by applying certain constructive ownership rules, by five or fewer individuals during the last half of each taxable year. In addition, we must meet certain other organizational requirements, including, but not limited to, that (i) the beneficial ownership in us is evidenced by transferable shares and (ii) we are managed by one or more trustees. We believe that we have satisfied all of these tests and all other organizational requirements and that we will continue to do so in the future. In order to ensure compliance with the 100 person test and the 50% share ownership test discussed above, we have placed certain restrictions on the transfer of our shares that are intended to prevent further concentration of share ownership. However, such restrictions may not prevent us from failing these requirements, and thereby failing to qualify as a REIT.

Gross Income Tests . To qualify as a REIT, we must satisfy two gross income tests:

To qualify as rents from real property for the purpose of satisfying the gross income tests, rental payments must generally be received from unrelated persons and not be based on the net income of the resident. Also, the rent attributable to personal property must not exceed 15% of the total rent. We may generally provide services to residents without “tainting” our rental income only if such services are “usually or customarily rendered” in connection with the rental of real property and not otherwise considered “impermissible services”. If such services are impermissible, then we may generally provide them only if they are considered de minimis in amount, or are provided through an independent contractor from whom we derive no revenue and that meets other requirements, or through a taxable REIT subsidiary. We believe that services provided to residents by us either are usually or customarily rendered in connection with the rental of real property and not otherwise considered impermissible, or, if considered impermissible services, will meet the de minimis test or will be provided by an independent contractor or taxable REIT subsidiary. However, we cannot provide any assurance that the Internal Revenue Service will agree with these positions.

If we fail to satisfy one or both of the gross income tests for any taxable year, we may nevertheless qualify as a REIT for the year if we are entitled to relief under certain provisions of the Internal Revenue Code. In this case, a penalty tax would still be applicable as discussed above. Generally, it is not possible to state whether in all circumstances we would be entitled to the benefit of these relief provisions and in the event these relief provisions do not apply, we will not qualify as a REIT.

Asset Tests . In general, at the close of each quarter of our taxable year, we must satisfy four tests relating to the nature of our assets:

17

Table of Contents

The 10% value test described in clause (3) (b) above does not apply to certain securities that fall within a safe harbor under the Code. Under the safe harbor, the following are not considered “securities” held by us for purposes of this 10% value test: (i) straight debt securities, (ii) any loan of an individual or an estate, (iii) certain rental agreements for the use of tangible property, (iv) any obligation to pay rents from real property, (v) any security issued by a state or any political subdivision thereof, foreign government or Puerto Rico only if the determination of any payment under such security is not based on the profits of another entity or payments on any obligation issued by such other entity, or (vi) any security issued by a REIT. The timing and payment of interest or principal on a security qualifying as straight debt may be subject to a contingency provided that (A) such contingency does not change the effective yield to maturity, not considering a de minimis change which does not exceed the greater of ¹ / 4 of 1% or 5% of the annual yield to maturity or we own $1,000,000 or less of the aggregate issue price or value of the particular issuer’s debt and not more than 12 months of unaccrued interest can be required to be prepaid or (B) the contingency is consistent with commercial practice and the contingency is effective upon a default or the exercise of a prepayment right by the issuer of the debt. If we hold indebtedness from any issuer, including a REIT, the indebtedness will be subject to, and may cause a violation of, the asset tests, unless it is a qualifying real estate asset or otherwise satisfies the above safe harbor. We currently own equity interests in certain entities that have elected to be taxed as REITs for federal income tax purposes and are not publicly traded. If any such entity were to fail to qualify as a REIT, we would not meet the 10% voting stock limitation and the 10% value limitation and we would, unless certain relief provisions applied, fail to qualify as a REIT. We believe that we and each of the REITs we own an interest in have and will comply with the foregoing asset tests for REIT qualification. However, we cannot provide any assurance that the Internal Revenue Service will agree with our determinations.

If we fail to satisfy the 5% or 10% asset tests described above after a 30-day cure period provided in the Internal Revenue Code, we will be deemed to have met such tests if the value of our non-qualifying assets is de minimis (i.e., does not exceed the lesser of 1% of the total value of our assets at the end of the applicable quarter or $10,000,000) and we dispose of the non-qualifying assets within six months after the last day of the quarter in which the failure to satisfy the asset tests is discovered. For violations due to reasonable cause and not willful neglect that are in excess of the de minimis exception described above, we may avoid disqualification as a REIT under any of the asset tests, after the 30-day cure period, by disposing of sufficient assets to meet the asset test within such six month period, paying a tax equal to the greater of $50,000 or the highest corporate tax rate multiplied by the net income generated by the non-qualifying assets and disclosing certain information to the Internal Revenue Service. If we cannot avail ourselves of these relief provisions, or if we fail to timely cure any noncompliance with the asset tests, we would cease to qualify as a REIT.

Annual Distribution Requirements . To qualify as a REIT, we are generally required to distribute dividends, other than capital gain dividends, to our shareholders each year in an amount at least equal to 90% of our REIT taxable income. These distributions must be paid either in the taxable year to which they relate, or in the following taxable year if declared before we timely file our tax return for the prior year and if paid with or before the first regular dividend payment date after the declaration is made. We intend to make timely distributions sufficient to satisfy our annual distribution requirements. To the extent that we do not distribute all of our net capital gain or distribute at least 90%, but less than 100% of our REIT taxable income, as adjusted, we are subject to tax on these amounts at regular corporate rates. We will be subject to a 4% excise tax on the excess of the required distribution over the sum of amounts actually distributed and amounts retained for which federal income tax was paid, if we fail to distribute during each calendar year at least the sum of: (1) 85% of our REIT ordinary income for the year; (2) 95% of our REIT capital gain net income for the year; and (3) any undistributed taxable income from prior taxable years. A REIT may elect to retain rather than distribute all or a portion of its net capital gains and pay the tax on the gains. In that case, a REIT may elect to have its shareholders include their proportionate share of the undistributed net capital gains in income as long-term capital gains and receive a credit for their share of the tax paid by the REIT. For purposes of the 4% excise tax described above, any retained amounts would be treated as having been distributed.

Ownership of Partnership Interests By Us . As a result of our ownership of the Operating Partnership, we will be considered to own and derive our proportionate share of the assets and items of income of the Operating Partnership, respectively, for purposes of the REIT asset and income tests, including its share of assets and items of income of any subsidiaries that are partnerships or limited liability companies.

18

Table of Contents

State and Local Taxes . We may be subject to state or local taxation in various jurisdictions, including those in which we transact business or reside. Generally REITs have seen increases in state and local taxes in recent years. Our state and local tax treatment may not conform to the federal income tax treatment discussed above. Consequently, prospective shareholders should consult their own tax advisors regarding the effect of state and local tax laws on an investment in common shares.

Taxation of Domestic Shareholders Subject to U.S. Tax

General . If we qualify as a REIT, distributions made to our taxable domestic shareholders with respect to their common shares, other than capital gain distributions and distributions attributable to taxable REIT subsidiaries, will be treated as ordinary income to the extent that the distributions come out of earnings and profits. These distributions will not be eligible for the dividends received deduction for shareholders that are corporations nor will they constitute “qualified dividend income” under the Internal Revenue Code, meaning that such dividends will be taxed at marginal rates applicable to ordinary income rather than the special capital gain rates currently applicable to qualified dividend income distributed to shareholders who satisfy applicable holding period requirements. In determining whether distributions are out of earnings and profits, we will allocate our earnings and profits first to preferred shares and second to the common shares. The portion of ordinary dividends which represent ordinary dividends we receive from a TRS, will be designated as “qualified dividend income” to REIT shareholders and are currently (for the 2010 tax year) eligible for preferential tax rates if paid to our non-corporate shareholders.

To the extent we make distributions to our taxable domestic shareholders in excess of our earnings and profits, such distributions will be considered a return of capital. Such distributions will be treated as a tax-free distribution and will reduce the tax basis of a shareholder’s common shares by the amount of the distribution so treated. To the extent such distributions cumulatively exceed a taxable domestic shareholder’s tax basis, such distributions are taxable as gain from the sale of shares. Shareholders may not include in their individual income tax returns any of our net operating losses or capital losses.

Dividends declared by a REIT in October, November, or December are deemed to have been paid by the REIT and received by its shareholders on December 31 of that year, so long as the dividends are actually paid during January of the following year. However, this treatment only applies to the extent of the REIT’s earnings and profits existing on December 31. To the extent the shareholder distribution paid in January exceeds available earnings and profits as of December 31, the excess will be treated as a distribution taxable to shareholders in the year paid. As such, for tax reporting purposes, January distributions paid to our shareholders may be split between two tax years.

Distributions made by us that we properly designate as capital gain dividends will be taxable to taxable domestic shareholders as gain from the sale or exchange of a capital asset held for more than one year. This treatment applies only to the extent that the designated distributions do not exceed our actual net capital gain for the taxable year. It applies regardless of the period for which a domestic shareholder has held his or her common shares. Despite this general rule, corporate shareholders may be required to treat up to 20% of certain capital gain dividends as ordinary income.

Generally, we will classify a portion of our designated capital gain dividends as a 15% rate gain distribution and the remaining portion as an unrecaptured Section 1250 gain distribution. A 15% rate gain distribution would be taxable to taxable domestic shareholders that are individuals, estates or trusts at a maximum rate of 15% (which 15% rate is currently scheduled to increase to 20% for taxable years beginning on and after January 1, 2011). An unrecaptured Section 1250 gain distribution would be taxable to taxable domestic shareholders that are individuals, estates or trusts at a maximum rate of 25%.

If, for any taxable year, we elect to designate as capital gain dividends any portion of the dividends paid or made available for the year to holders of all classes of shares of beneficial interest, then the portion of the capital gains dividends that will be allocable to the holders of common shares will be the total capital gain dividends multiplied by a fraction. The numerator of the fraction will be the total dividends paid or made available to the holders of the common shares for the year. The denominator of the fraction will be the total dividends paid or made available to holders of all classes of shares of beneficial interest.

We may elect to retain (rather than distribute as is generally required) net capital gain for a taxable year and pay the income tax on that gain. If we make this election, shareholders must include in income, as long-term capital gain, their proportionate share of the undistributed net capital gain. Shareholders will be treated as having paid their proportionate share of the tax paid by us on these gains. Accordingly, they will receive a tax credit or refund for the amount. Shareholders will increase the basis in their common shares by the difference between the amount of capital

19

Table of Contents

gain included in their income and the amount of the tax they are treated as having paid. Our earnings and profits will be adjusted appropriately.

In general, a shareholder will recognize gain or loss for federal income tax purposes on the sale or other disposition of common shares in an amount equal to the difference between:

The gain or loss will be capital gain or loss if the common shares were held as a capital asset. Generally, the capital gain or loss will be long-term capital gain or loss if the common shares were held for more than one year.

In general, a loss recognized by a shareholder upon the sale of common shares that were held for six months or less, determined after applying certain holding period rules, will be treated as long-term capital loss to the extent that the shareholder received distributions that were treated as long-term capital gains. For shareholders who are individuals, trusts and estates, the long-term capital loss will be apportioned among the applicable long-term capital gain rates to the extent that distributions received by the shareholder were previously so treated.

Taxation of Domestic Tax-Exempt Shareholders

Most tax-exempt organizations are not subject to federal income tax except to the extent of their unrelated business taxable income, which is often referred to as UBTI. Unless a tax-exempt shareholder holds its common shares as debt financed property or uses the common shares in an unrelated trade or business, distributions to the shareholder should not constitute UBTI. Similarly, if a tax-exempt shareholder sells common shares, the income from the sale should not constitute UBTI unless the shareholder held the shares as debt financed property or used the shares in a trade or business.

However, for tax-exempt shareholders that are social clubs, voluntary employee benefit associations, supplemental unemployment benefit trusts, and qualified group legal services plans, income from owning or selling common shares will constitute UBTI unless the organization is able to properly deduct amounts set aside or placed in reserve so as to offset the income generated by its investment in common shares. These shareholders should consult their own tax advisors concerning these set aside and reserve requirements which are set forth in the Internal Revenue Code.

In addition, certain pension trusts that own more than 10% of a “pension-held REIT” must report a portion of the distributions that they receive from the REIT as UBTI. We have not been and do not expect to be treated as a pension-held REIT for purposes of this rule.

Taxation of Foreign Shareholders

The following is a discussion of certain anticipated United States federal income tax consequences of the ownership and disposition of common shares applicable to a foreign shareholder. For purposes of this discussion, a “foreign shareholder” is any person other than:

Distributions by Us . Distributions by us to a foreign shareholder that are neither attributable to gain from sales or exchanges by us of United States real property interests nor designated by us as capital gains dividends will be treated as dividends of ordinary income to the extent that they are made out of our earnings and profits. These distributions ordinarily will be subject to withholding of United States federal income tax on a gross basis at a 30% rate, or a lower treaty rate, unless the dividends are treated as effectively connected with the conduct by the foreign shareholder of a United States trade or business. Please note that under certain treaties lower withholding rates generally applicable to dividends do not apply to dividends from REITs. Dividends that are effectively connected with

20

Table of Contents

a United States trade or business will be subject to tax on a net basis at graduated rates, and are generally not subject to withholding. Certification and disclosure requirements must be satisfied before a dividend is exempt from withholding under this exemption. A foreign shareholder that is a corporation also may be subject to an additional branch profits tax at a 30% rate or a lower treaty rate.

We expect to withhold United States income tax at the rate of 30% on any such distributions made to a foreign shareholder unless:

If such distribution is in excess of our current or accumulated earnings and profits, it will not be taxable to a foreign shareholder to the extent that the distribution does not exceed the adjusted basis of the shareholder’s common shares. Instead, the distribution will reduce the adjusted basis of the common shares. To the extent that the distribution exceeds the adjusted basis of the common shares, it will give rise to gain from the sale or exchange of the shareholder’s common shares. The tax treatment of this gain is described below.

We intend to withhold at a rate of 30%, or a lower applicable treaty rate, on the entire amount of any distribution not designated as a capital gain distribution. In such event, a foreign shareholder may seek a refund of the withheld amount from the IRS if it is subsequently determined that the distribution was, in fact, in excess of our earnings and profits, and the amount withheld exceeded the foreign shareholder’s United States tax liability with respect to the distribution.

Any capital gain dividend with respect to any class of our stock which is “regularly traded” on an established securities market, will be treated as an ordinary dividend described above, if the foreign shareholder did not own more than 5% of such class of stock at any time during the one year period ending on the date of the distribution. Foreign shareholders generally will not be required to report such distributions received from us on U.S. federal income tax returns and all distributions treated as dividends for U.S. federal income tax purposes, including any capital gain dividends, will be subject to a 30% U.S. withholding tax (unless reduced or eliminated under an applicable income tax treaty), as described above. In addition, the branch profits tax will no longer apply to such distributions.

Distributions to a foreign shareholder that we designate at the time of the distributions as capital gain dividends, other than those arising from the disposition of a United States real property interest, generally will not be subject to United States federal income taxation unless:

Under the Foreign Investment in Real Property Tax Act, which is known as FIRPTA, distributions to a foreign shareholder that are attributable to gain from sales or exchanges of United States real property interests will cause the foreign shareholder to be treated as recognizing the gain as income effectively connected with a United States trade or business. This rule applies whether or not a distribution is designated as a capital gain dividend. Accordingly, foreign shareholders generally would be taxed on these distributions at the same rates applicable to U.S. shareholders, subject to a special alternative minimum tax in the case of nonresident alien individuals. In addition, a foreign corporate shareholder might be subject to the branch profits tax discussed above, as well as U.S. federal income tax return filing requirements. We are required to withhold 35% of these distributions. The withheld amount can be credited against the foreign shareholder’s United States federal income tax liability.

Although the law is not entirely clear on the matter, it appears that amounts we designate as undistributed capital gains in respect of the common shares held by U.S. shareholders would be treated with respect to foreign shareholders in the same manner as actual distributions of capital gain dividends. Under that approach, foreign

21

Table of Contents

shareholders would be able to offset as a credit against their United States federal income tax liability their proportionate share of the tax paid by us on these undistributed capital gains. In addition, if timely requested, foreign shareholders might be able to receive from the IRS a refund to the extent their proportionate share of the tax paid by us were to exceed their actual United States federal income tax liability.

Foreign Shareholders’ Sales of Common Shares . Gain recognized by a foreign shareholder upon the sale or exchange of common shares generally will not be subject to United States taxation unless the shares constitute a “United States real property interest” within the meaning of FIRPTA. The common shares will not constitute a United States real property interest so long as we are a domestically controlled REIT. A domestically controlled REIT is a REIT in which at all times during a specified testing period less than 50% in value of its stock is held directly or indirectly by foreign shareholders. We believe that we are a domestically controlled REIT. Therefore, we believe that the sale of common shares will not be subject to taxation under FIRPTA. However, because common shares and preferred shares are publicly traded, we cannot guarantee that we will continue to be a domestically controlled REIT. In any event, gain from the sale or exchange of common shares not otherwise subject to FIRPTA will be subject to U.S. tax, if either:

Even if we do not qualify as or cease to be a domestically controlled REIT, gain arising from the sale or exchange by a foreign shareholder of common shares still would not be subject to United States taxation under FIRPTA as a sale of a United States real property interest if:

If gain on the sale or exchange of common shares were subject to taxation under FIRPTA, the foreign shareholder would be subject to regular United States income tax with respect to the gain in the same manner as a taxable U.S. shareholder, subject to any applicable alternative minimum tax, a special alternative minimum tax in the case of nonresident alien individuals and the possible application of the branch profits tax in the case of foreign corporations. The purchaser of the common shares would be required to withhold and remit to the IRS 10% of the purchase price.

Information Reporting Requirement and Backup Withholding

We will report to our domestic shareholders and the Internal Revenue Service the amount of distributions paid during each calendar year and the amount of tax withheld, if any. Under certain circumstances, domestic shareholders may be subject to backup withholding. Backup withholding will apply only if such domestic shareholder fails to furnish certain information to us or the Internal Revenue Service. Backup withholding will not apply with respect to payments made to certain exempt recipients, such as corporations and tax-exempt organizations. Domestic shareholders should consult their own tax advisors regarding their qualification for exemption from backup withholding and the procedure for obtaining such an exemption. Backup withholding is not an additional tax. Rather, the amount of any backup withholding with respect to a payment to a domestic shareholder will be allowed as a credit against such person’s United States federal income tax liability and may entitle such person to a refund, provided that the required information is timely furnished to the Internal Revenue Service.

None.

22

Table of Contents

As of December 31, 2009, the Company, directly or indirectly through investments in title holding entities, owned all or a portion of 495 properties in 23 states and the District of Columbia consisting of 137,007 units. The Company’s properties are summarized by building type in the following table:

The Company’s properties are summarized by ownership type in the following table:

The following table sets forth certain information by market relating to the Company’s properties at December 31, 2009:

PORTFOLIO SUMMARY

23

Table of Contents

The Company’s properties had an average occupancy of approximately 93.9% at December 31, 2009. Certain of the Company’s properties are encumbered by mortgages and additional detail can be found on Schedule III – Real Estate and Accumulated Depreciation. Resident leases are generally for twelve months in length and can require security deposits. The garden-style properties are generally defined as properties with two and/or three story buildings while the mid-rise/high-rise are defined as properties with greater than three story buildings. These two property types typically provide residents with amenities, which may include a clubhouse, swimming pool, laundry facilities and cable television access. Certain of these properties offer additional amenities such as saunas, whirlpools, spas, sports courts and exercise rooms or other amenities. The military housing properties are defined as those properties located on military bases.

The distribution of the properties throughout the United States reflects the Company’s belief that geographic diversification helps insulate the portfolio from regional and economic influences. At the same time, the Company has sought to create clusters of properties within each of its primary markets in order to achieve economies of scale in management and operation. The Company may nevertheless acquire additional multifamily properties located anywhere in the United States.

The properties currently in various stages of development at December 31, 2009 are included in the following table:

24

Table of Contents

Consolidated Development Projects as of December 31, 2009

(Amounts in thousands except for project and unit amounts)

25

Table of Contents

The Company is party to a housing discrimination lawsuit brought by a non-profit civil rights organization in April 2006 in the U.S. District Court for the District of Maryland. The suit alleges that the Company designed and built approximately 300 of its properties in violation of the accessibility requirements of the Fair Housing Act and Americans With Disabilities Act. The suit seeks actual and punitive damages, injunctive relief (including modification of non-compliant properties), costs and attorneys’ fees. The Company believes it has a number of viable defenses, including that a majority of the named properties were completed before the operative dates of the statutes in question and/or were not designed or built by the Company. Accordingly, the Company is defending the suit vigorously. Due to the pendency of the Company’s defenses and the uncertainty of many other critical factual and legal issues, it is not possible to determine or predict the outcome of the suit and as a result, no amounts have been accrued at December, 31, 2009. While no assurances can be given, the Company does not believe that the suit, if adversely determined, would have a material adverse effect on the Company.

The Company does not believe there is any other litigation pending or threatened against it that, individually or in the aggregate, reasonably may be expected to have a material adverse effect on the Company.

None.

26

Table of Contents

Common Share Market Prices and Dividends

The following table sets forth, for the years indicated, the high, low and closing sales prices for and the distributions declared on the Company’s Common Shares, which trade on the New York Stock Exchange under the trading symbol EQR.

The number of record holders of Common Shares at February 19, 2010 was approximately 3,400. The number of outstanding Common Shares as of February 19, 2010 was 281,884,878.

Unregistered Common Shares Issued in the Quarter Ended December 31, 2009

During the quarter ended December 31, 2009, the Company issued 234,973 Common Shares in exchange for 234,973 OP Units held by various limited partners of the Operating Partnership. OP Units are generally exchangeable into Common Shares of EQR on a one-for-one basis or, at the option of the Operating Partnership, the cash equivalent thereof, at any time one year after the date of issuance. Some of these shares were issued in reliance on exemptions from registration under Section 4(2) of the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder, as these were transactions by an issuer not involving a public offering. In light of the manner of the sale and information obtained by the Company from the limited partners in connection with these transactions, the Company believes it may rely on these exemptions.

Equity Compensation Plan Information

The following table provides information as of December 31, 2009 with respect to the Company’s Common Shares that may be issued under its existing equity compensation plans.

27

Table of Contents

The aggregate number of securities available for issuance (inclusive of restricted shares previously granted and outstanding and shares underlying outstanding options) under the 2002 Plan equals 7.5% of the Company’s outstanding Common Shares, calculated on a fully diluted basis, determined annually on the first day of each calendar year. On January 1, 2010, this amount equaled 22,091,629, of which 6,295,992 shares were available for future issuance. No awards may be granted under the 2002 Plan after February 20, 2012.

The following table sets forth selected financial and operating information on a historical basis for the Company. The following information should be read in conjunction with all of the financial statements and notes thereto included elsewhere in this Form 10-K. The historical operating and balance sheet data have been derived from the historical financial statements of the Company. All amounts have also been restated in accordance with the guidance on discontinued operations, noncontrolling interests and convertible debt. Certain capitalized terms as used herein are defined in the Notes to Consolidated Financial Statements.

28

Table of Contents

CONSOLIDATED HISTORICAL FINANCIAL INFORMATION

(Financial information in thousands except for per share and property data)