Interests in the Aimco Operating Partnership that are held by limited partners other than Aimco are reflected in the accompanying balance sheets as noncontrolling interests in Aimco Operating Partnership. Interests in partnerships consolidated into the Aimco Operating Partnership that are held by third parties are reflected in the accompanying balance sheets as noncontrolling interests in consolidated real estate partnerships. The assets of consolidated real estate partnerships owned or controlled by us generally are not available to pay creditors of Aimco or the Aimco Operating Partnership.

As used herein, and except where the context otherwise requires, “partnership” refers to a limited partnership or a limited liability company and “partner” refers to a partner in a limited partnership or a member in a limited liability company.

Variable Interest Entities

We consolidate all variable interest entities for which we are the primary beneficiary. Generally, a variable interest entity, or VIE, is an entity with one or more of the following characteristics: (a) the total equity investment at risk is not sufficient to permit the entity to finance its activities without additional subordinated financial support; (b) as a group, the holders of the equity investment at risk lack (i) the ability to make decisions about an entity’s activities through voting or similar rights, (ii) the obligation to absorb the expected losses of the entity, or (iii) the right to receive the expected residual returns of the entity; or (c) the equity investors have voting rights that are not proportional to their economic interests and substantially all of the entity’s activities either involve, or are conducted on behalf of, an investor that has disproportionately few voting rights.

Effective January 1, 2010, we adopted the provisions of FASB Accounting Standards Update 2009-17, Improvements to Financial Reporting by Enterprises Involved with Variable Interest Entities, or ASU 2009-17, on a prospective basis. ASU 2009-17, which modified the guidance in FASB ASC Topic 810, introduced a more qualitative approach to evaluating VIEs for consolidation and requires a company to perform an analysis to determine whether its variable interests give it a controlling financial interest in a VIE. This analysis identifies the primary beneficiary of a VIE as the entity that has (a) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance, and (b) the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. In determining whether it has the power to direct the activities of the VIE that most significantly affect the VIE’s performance, ASU 2009-17 requires a company to assess whether it has an implicit financial responsibility to ensure that a VIE operates as designed, requires continuous reassessment of primary beneficiary status rather than periodic, event-driven assessments as previously required, and incorporates expanded disclosure requirements.

In determining whether we are the primary beneficiary of a VIE, we consider qualitative and quantitative factors, including, but not limited to: which activities most significantly impact the VIEs economic performance and which party controls such activities; the amount and characteristics of our investment; the obligation or likelihood for us or other investors to provide financial support; and the similarity with and significance to the business activities of us and the other investors. Significant judgments related to these determinations include estimates about the current and future fair values and performance of real estate held by these VIEs and general market conditions.

As a result of our adoption of ASU 2009-17, we concluded we are the primary beneficiary of, and therefore consolidated, 49 previously unconsolidated partnerships. Those partnerships own, or control other entities that own, 31 apartment properties. Our direct and indirect interests in the profits and losses of those partnerships range from less than 1% to 35%, and average approximately 7%. We applied the practicability exception for initial measurement of consolidated VIEs to partnerships that own 13 properties and accordingly recognized the consolidated assets, liabilities and noncontrolling interests at fair value effective January 1, 2010 (refer to the Fair Value Measurements section for further information regarding certain of the fair value amounts recognized upon consolidation). We deconsolidated partnerships that own ten apartment properties in which we hold an average interest of approximately 55%. The initial consolidation and deconsolidation of these partnerships resulted in increases (decreases), net of intercompany eliminations, in amounts included in our consolidated balance sheet as of January 1, 2010, as follows (in thousands):


	Consolidation			Deconsolidation
Real estate, net	$	143,986		$	(86,151	)
Cash and cash equivalents and restricted cash		25,056			(7,425	)
Accounts and notes receivable		(12,249	)		6,002
Investment in unconsolidated real estate partnerships		31,579			11,302
Other assets		3,870			(1,084	)

Total assets	$	192,242		$	(77,356	)


Total indebtedness	$	129,164		$	(56,938	)
Accrued and other liabilities		34,426			(14,921	)

Total liabilities		163,590			(71,859	)

Cumulative effect of a change in accounting principle:
Noncontrolling interests		59,380			(8,501	)
Aimco		(30,728	)		3,004

Total equity		28,652			(5,497	)

Total liabilities and equity	$	192,242		$	(77,356	)

In periods prior to 2009, when consolidated real estate partnerships made cash distributions to partners in excess of the carrying amount of the noncontrolling interest, we generally recorded a charge to earnings equal to the amount of such excess distribution, even though there was no economic effect or cost. Also prior to 2009, we allocated the noncontrolling partners’ share of partnership losses to noncontrolling partners to the extent of the carrying amount of the noncontrolling interest. Consolidation of a partnership does not ordinarily result in a change to the net amount of partnership income or loss that is recognized using the equity method. However, prior to 2009, when a partnership had a deficit in equity, accounting principles generally accepted in the United States of America, or GAAP, may have required the controlling partner that consolidates the partnership to recognize any losses that would otherwise be allocated to noncontrolling partners, in addition to the controlling partner’s share of losses. Certain of the partnerships that we consolidated in accordance with ASU 2009-17 had deficits in equity that resulted from losses or deficit distributions during prior periods when we accounted for our investment using the equity method. We would have been required to recognize the noncontrolling partners’ share of those losses had we consolidated those partnerships in those periods prior to 2009. In accordance with our prospective transition method for the adoption of ASU 2009-17 related to our consolidation of previously unconsolidated partnerships, we recorded a $30.7 million charge to our equity, the majority of which was attributed to the cumulative amount of additional losses that we would have recognized had we applied ASU 2009-17 in periods prior to 2009. Substantially all of those losses were attributable to real estate depreciation expense.

Our consolidated statements of operations for the year ended December 31, 2010, include the following amounts for the entities and related real estate properties consolidated as of January 1, 2010 (for both continuing and discontinued operations), in accordance with ASU 2009-17 (in thousands):


	2010
Rental and other property revenues	$	32,216
Property operating expenses		(19,192	)
Depreciation and amortization		(10,624	)
Other expenses		(2,038	)

Operating income		362
Interest income		33
Interest expense		(8,370	)
Equity in losses of unconsolidated real estate partnerships		(17,895	)
Gain on disposition of unconsolidated real estate and other		7,360

Net loss		(18,510	)
Net loss attributable to noncontrolling interests in consolidated real estate partnerships		19,328
Net income attributable to noncontrolling interests in the Aimco Operating Partnership		(57	)

Net income attributable to Aimco	$	761

Our equity in the results of operations of the partnerships and related properties we deconsolidated in connection with our adoption of ASU 2009-17 is included in equity in earnings or losses of unconsolidated real estate partnerships in our consolidated statements of operations for the year ended December 31, 2010. The amounts related to these entities are not significant.

As of December 31, 2010, we were the primary beneficiary of, and therefore consolidated, approximately 137 VIEs, which owned 96 apartment properties with 14,054 units (inclusive of properties sold or classified as held for sale through March 31, 2011). Real estate with a carrying value of $867.1 million collateralized $654.3 million of debt of those VIEs. Any significant amounts of assets and liabilities related to our consolidated VIEs are identified parenthetically on our accompanying condensed consolidated balance sheets. The creditors of the consolidated VIEs do not have recourse to our general credit.

As of December 31, 2010, we also held variable interests in 276 VIEs for which we were not the primary beneficiary. Those VIEs consist primarily of partnerships that are engaged, directly or indirectly, in the ownership and management of 329 apartment properties with 20,570 units. We are involved with those VIEs as an equity holder, lender, management agent, or through other contractual relationships. The majority of our investments in unconsolidated VIEs, or approximately $48.9 million at December 31, 2010, are held through consolidated investment partnerships that are VIEs and in which we generally hold a 1% or less general partner or equivalent interest. Accordingly, substantially all of the investment balances related to these unconsolidated VIEs are attributed to the noncontrolling interests in the consolidated investment partnerships that hold the investments in these unconsolidated VIEs. Our maximum risk of loss related to our investment in these VIEs is generally limited to our equity interest in the consolidated investment partnerships, which is insignificant. The remainder of our investment in unconsolidated VIEs, or approximately $5.5 million at December 31, 2010, is held through consolidated investment partnerships that are VIEs and in which we hold substantially all of the economic interests. Our maximum risk of loss related to our investment in these VIEs is limited to our $5.5 million recorded investment in such entities.

In addition to our investments in unconsolidated VIEs discussed above, at December 31, 2010, we had in aggregate $101.7 million of receivables from unconsolidated VIEs and we had a contractual obligation to advance funds to certain unconsolidated VIEs totaling $3.8 million. Our maximum risk of loss associated with our lending and management activities related to these unconsolidated VIEs is limited to these amounts. We may be subject to additional losses to the extent of any receivables relating to future provision of services to these entities or financial support that we voluntarily provide.

Acquisition of Real Estate Assets and Related Depreciation and Amortization

We adopted the provisions of FASB Statement of Financial Accounting Standards No. 141(R), Business Combinations — a replacement of FASB Statement No. 141, or SFAS 141(R), which are codified in FASB ASC Topic 805, effective January 1, 2009. These provisions apply to all transactions or events in which an entity obtains control of one or more businesses, including those effected without the transfer of consideration, for example, by contract or through a lapse of minority veto rights. These provisions require the acquiring entity in a business combination to recognize the full fair value of assets acquired and liabilities assumed in the transaction (whether a full or partial acquisition); establish the acquisition-date fair value as the measurement objective for all assets acquired and liabilities assumed; and require expensing of most transaction and restructuring costs.

We believe most operating real estate assets meet SFAS 141(R)’s revised definition of a business. Accordingly, in connection with our 2009 adoption of SFAS 141(R), we retroactively adjusted our results of operations for the year ended December 31, 2008, to expense $3.5 million of transaction costs incurred prior to December 31, 2008. This retroactive adjustment is reflected in investment management expenses in our accompanying consolidated statements of operations and reduced basic and diluted earnings per share amounts by $0.04 for the year ended December 31, 2008.

Effective January 1, 2009, we recognize at fair value the acquisition of properties or interests in partnerships that own properties if the transaction results in consolidation and we expense as incurred most related transaction costs. We allocate the cost of acquired properties to tangible assets and identified intangible assets based on their fair values. We determine the fair value of tangible assets, such as land, building, furniture, fixtures and equipment, generally using internal valuation techniques that consider comparable market transactions, discounted cash flow techniques, replacement costs and other available information. We determine the fair value of identified intangible assets (or liabilities), which typically relate to in-place leases, using internal valuation techniques that consider the terms of the in-place leases, current market data for comparable leases, and our experience in leasing similar properties. The intangible assets or liabilities related to in-place leases are comprised of:

The value of the above- and below-market leases in-place. An asset or liability is recognized based on the difference between (a) the contractual amounts to be paid pursuant to the in-place leases and (b) our estimate of fair market lease rates for the corresponding in-place leases, measured over the period, including estimated lease renewals for below-market leases, that the leases are expected to remain in effect.

The estimated unamortized portion of avoided leasing commissions and other costs that ordinarily would be incurred to acquire the in-place leases.

The value associated with vacant units during the absorption period (estimates of lost rental revenue during the expected lease-up periods based on current market demand and stabilized occupancy levels).

The values of the above- and below-market leases are amortized to rental revenue over the expected remaining terms of the associated leases which include reasonably assured renewal periods. Other intangible assets related to in-place leases are amortized to depreciation and amortization over the expected remaining terms of the associated leases. Amortization is adjusted, as necessary, to reflect any early lease terminations that were not anticipated in determining amortization periods.

Depreciation for all tangible real estate assets is calculated using the straight-line method over their estimated useful lives. Acquired buildings and improvements are depreciated over a composite life of 14 to 52 years, based on the age, condition and other physical characteristics of the property. As discussed under Impairment of Long Lived Assets below, we may adjust depreciation of properties that are expected to be disposed of or demolished prior to the end of their useful lives. Furniture, fixtures and equipment associated with acquired properties are depreciated over five years.

At December 31, 2010 and 2009, deferred income in our consolidated balance sheets includes below-market lease amounts totaling $27.9 million and $31.8 million, respectively, which are net of accumulated amortization of $24.9 million and $21.0 million, respectively. During the years ended December 31, 2010, 2009 and 2008, we included amortization of below-market leases of $3.9 million, $4.4 million and $4.4 million, respectively, in rental and other property revenues in our consolidated statements of operations. At December 31, 2010, our below-market leases had a weighted average amortization period of 7.0 years and estimated aggregate amortization for each of the five succeeding years as follows (in millions):


	2011		2012		2013		2014		2015
Estimated amortization	$	3.6	$	3.2	$	2.8	$	2.5	$	2.3

Capital Additions and Related Depreciation

We capitalize costs, including certain indirect costs, incurred in connection with our capital additions activities, including redevelopment and construction projects, other tangible property improvements, and replacements of existing property components. Included in these capitalized costs are payroll costs associated with time spent by site employees in connection with the planning, execution and control of all capital additions activities at the property level. We characterize as “indirect costs” an allocation of certain department costs, including payroll, at the area operations and corporate levels that clearly relate to capital additions activities. We capitalize interest, property taxes and insurance during periods in which redevelopment and construction projects are in progress. We charge to expense as incurred costs that do not relate to capital expenditure activities, including ordinary repairs, maintenance, resident turnover costs and general and administrative expenses.

We depreciate capitalized costs using the straight-line method over the estimated useful life of the related component or improvement, which is generally five, 15 or 30 years. All capitalized site payroll and indirect costs are allocated proportionately, based on direct costs, among capital projects and depreciated over the estimated useful lives of such projects.

Certain homogeneous items that are purchased in bulk on a recurring basis, such as carpeting and appliances, are depreciated using group methods that reflect the average estimated useful life of the items in each group. Except in the case of property casualties, where the net book value of lost property is written off in the determination of casualty gains or losses, we generally do not recognize any loss in connection with the replacement of an existing property component because normal replacements are considered in determining the estimated useful lives used in connection with our composite and group depreciation methods.

For the years ended December 31, 2010, 2009 and 2008, for continuing and discontinued operations, we capitalized $11.6 million, $9.8 million and $25.7 million of interest costs, respectively, and $25.3 million, $40.0 million and $78.1 million of site payroll and indirect costs, respectively.

Impairment of Long-Lived Assets

Real estate and other long-lived assets to be held and used are stated at cost, less accumulated depreciation and amortization, unless the carrying amount of the asset is not recoverable. If events or circumstances indicate that the carrying amount of a property may not be recoverable, we make an assessment of its recoverability by comparing the carrying amount to our estimate of the undiscounted future cash flows, excluding interest charges, of the property. If the carrying amount exceeds the aggregate undiscounted future cash flows, we recognize an impairment loss to the extent the carrying amount exceeds the estimated fair value of the property.

In connection with the preparation of our 2008 annual financial statements, we assessed the recoverability of our investment in our Lincoln Place property, located in Venice, California. Based upon the declines in land values in Southern California during 2008 and the expected timing of our redevelopment efforts, we determined that the total carrying amount of the property was no longer probable of full recovery and, accordingly, during the three months ended December 31, 2008, recognized an impairment loss of $85.4 million ($55.6 million net of tax).

Similarly, we assessed the recoverability of our investment in Pacific Bay Vistas (formerly Treetops), a vacant property located in San Bruno, California, and determined that the carrying amount of the property was no longer probable of full recovery and, accordingly, we recognized an impairment loss of $5.7 million for this property during the three months ended December 31, 2008.

In addition to the impairments of Lincoln Place and Pacific Bay Vistas, based on periodic tests of recoverability of long-lived assets, for the years ended December 31, 2010 and 2009, we recorded real estate impairment losses of $0.4 million and $2.3 million, respectively, related to properties classified as held for use. For the year ended December 31, 2008, we recorded no similar impairment losses related to properties classified as held for use.

We report impairment losses or recoveries related to properties sold or classified as held for sale in discontinued operations.

Our tests of recoverability address real estate assets that do not currently meet all conditions to be classified as held for sale, but are expected to be disposed of prior to the end of their estimated useful lives. If an impairment loss is not required to be recorded, the recognition of depreciation is adjusted prospectively, as necessary, to reduce the carrying amount of the real estate to its estimated disposition value over the remaining period that the real estate is expected to be held and used. We also may adjust depreciation prospectively to reduce to zero the carrying amount of buildings that we plan to demolish in connection with a redevelopment project. These depreciation adjustments, after adjustments for noncontrolling interests, decreased net income available to Aimco common stockholders by $0.2 million, $18.3 million and $10.7 million, and resulted in decreases in basic and diluted earnings per share of less than $0.01, $0.16 and $0.12, for the years ended December 31, 2010, 2009 and 2008, respectively.

Cash Equivalents

We classify highly liquid investments with an original maturity of three months or less as cash equivalents.

Restricted Cash

Restricted cash includes capital replacement reserves, completion repair reserves, bond sinking fund amounts and tax and insurance escrow accounts held by lenders.

Accounts Receivable and Allowance for Doubtful Accounts

Accounts receivable are generally comprised of amounts receivable from residents, amounts receivable from non-affiliated real estate partnerships for which we provide property management and other services and other miscellaneous receivables from non-affiliated entities. We evaluate collectibility of accounts receivable from residents and establish an allowance, after the application of security deposits and other anticipated recoveries, for accounts greater than 30 days past due for current residents and all receivables due from former residents. Accounts receivable from residents are stated net of allowances for doubtful accounts of approximately $2.1 million and $1.4 million as of December 31, 2010 and 2009, respectively.

We evaluate collectibility of accounts receivable from non-affiliated entities and establish an allowance for amounts that are considered to be uncollectible. Accounts receivable relating to non-affiliated entities are stated net of allowances for doubtful accounts of approximately $1.0 million and $0.3 million as of December 31, 2010 and 2009, respectively.

Accounts Receivable and Allowance for Doubtful Accounts from Affiliates

Accounts receivable from affiliates are generally comprised of receivables related to property management and other services provided to unconsolidated real estate partnerships in which we have an ownership interest. We evaluate collectibility of accounts receivable balances from affiliates on a periodic basis, and establish an allowance for the amounts deemed to be uncollectible. Accounts receivable from affiliates are stated net of allowances for doubtful accounts of approximately $1.5 million and $1.9 million as of December 31, 2010 and 2009, respectively.

Deferred Costs

We defer lender fees and other direct costs incurred in obtaining new financing and amortize the amounts over the terms of the related loan agreements. Amortization of these costs is included in interest expense.

We defer leasing commissions and other direct costs incurred in connection with successful leasing efforts and amortize the costs over the terms of the related leases. Amortization of these costs is included in depreciation and amortization.

Notes Receivable from Unconsolidated Real Estate Partnerships and Non-Affiliates and Related Interest Income and Provision for Losses

Notes receivable from unconsolidated real estate partnerships and from non-affiliates represent our two portfolio segments, as defined in FASB Accounting Standards Update 2010-20, Disclosures about the Credit Quality of Financing Receivables and the Allowance for Credit Losses, that we use to evaluate for potential loan loss. Notes receivable from unconsolidated real estate partnerships consist primarily of notes receivable from partnerships in which we are the general partner but do not consolidate the partnership. These loans are typically due on demand, have no stated maturity date and may not require current payments of principal or interest. Notes receivable from non-affiliates have stated maturity dates and may require current payments of principal and interest. Repayment of these notes is subject to a number of variables, including the performance and value of the underlying real estate properties and the claims of unaffiliated mortgage lenders, which are generally senior to our claims. Our notes receivable consist of two classes: loans extended by us that we carry at the face amount plus accrued interest, which we refer to as “par value notes;” and loans extended by predecessors whose positions we generally acquired at a discount, which we refer to as “discounted notes.”

We record interest income on par value notes as earned in accordance with the terms of the related loan agreements. We discontinue the accrual of interest on such notes when the notes are impaired, as discussed below, or when there is otherwise significant uncertainty as to the collection of interest. We record income on such nonaccrual loans using the cost recovery method, under which we apply cash receipts first to the recorded amount of the loan; thereafter, any additional receipts are recognized as income.

We recognize interest income on discounted notes receivable based upon whether the amount and timing of collections are both probable and reasonably estimable. We consider collections to be probable and reasonably estimable when the borrower has closed or entered into certain pending transactions (which include real estate sales, refinancings, foreclosures and rights offerings) that provide a reliable source of repayment. In such instances, we recognize accretion income, on a prospective basis using the effective interest method over the estimated remaining term of the loans, equal to the difference between the carrying amount of the discounted notes and the estimated collectible value. We record income on all other discounted notes using the cost recovery method.

We assess the collectibility of notes receivable on a periodic basis, which assessment consists primarily of an evaluation of cash flow projections of the borrower to determine whether estimated cash flows are sufficient to repay principal and interest in accordance with the contractual terms of the note. We update our cash flow projections of the borrowers annually, and more frequently for certain loans depending on facts and circumstances. We recognize impairments on notes receivable when it is probable that principal and interest will not be received in accordance with the contractual terms of the loan. Factors that affect this assessment include the fair value of the partnership’s real estate, pending transactions to refinance the partnership’s senior obligations or sell the partnership’s real estate, and market conditions (current and forecasted) related to a particular asset. The amount of the impairment to be recognized generally is based on the fair value of the partnership’s real estate that represents the primary source of loan repayment. In certain instances where other sources of cash flow are available to repay the loan, the impairment is measured by discounting the estimated cash flows at the loan’s original effective interest rate. See Note 5 for further discussion of our notes receivable.

Investments in Unconsolidated Real Estate Partnerships

We own general and limited partner interests in partnerships that either directly, or through interests in other real estate partnerships, own apartment properties. We generally account for investments in real estate partnerships that we do not consolidate under the equity method. Under the equity method, our share of the earnings or losses of the entity for the periods being presented is included in equity in earnings (losses) from unconsolidated real estate partnerships, inclusive of our share of impairments and property disposition gains recognized by and related to such entities. Certain investments in real estate partnerships that were acquired in business combinations were determined to have insignificant value at the acquisition date and are accounted for under the cost method. Any distributions received from such partnerships are recognized as income when received.

The excess of the cost of the acquired partnership interests over the historical carrying amount of partners’ equity or deficit is ascribed generally to the fair values of land and buildings owned by the partnerships. We amortize the excess cost related to the buildings over the estimated useful lives of the buildings. Such amortization is recorded as a component of equity in earnings (losses) of unconsolidated real estate partnerships. See Note 4 for further discussion of Investments in Unconsolidated Real Estate Partnerships.

Intangible Assets

At December 31, 2010 and 2009, other assets included goodwill associated with our reportable segments of $67.1 million and $71.8 million, respectively. We perform an annual impairment test of goodwill that compares the fair value of reporting units with their carrying amounts, including goodwill. We determined that our goodwill was not impaired in 2010, 2009 or 2008.

During the years ended December 31, 2010 and 2009, we allocated $4.7 million and $10.1 million, respectively, of goodwill related to our reportable segments (conventional and affordable real estate operations) to the carrying amounts of the properties sold or classified as held for sale during those periods. The amounts of goodwill allocated to these properties were based on the relative fair values of the properties sold or classified as held for sale and the retained portions of the reporting units to which the goodwill as allocated. During 2008, we did not allocate any goodwill to properties sold or classified as held for sale as real estate properties were not considered businesses under then applicable GAAP.

Other assets also includes intangible assets for purchased management contracts with finite lives that we amortize on a straight-line basis over terms ranging from five to 20 years and intangible assets for in-place leases as discussed under Acquisition of Real Estate Assets and Related Depreciation and Amortization.

Capitalized Software Costs

Purchased software and other costs related to software developed for internal use are capitalized during the application development stage and are amortized using the straight-line method over the estimated useful life of the software, generally five years. We write-off the costs of software development projects when it is no longer probable that the software will be completed and placed in service. For the years ended December 31, 2010, 2009 and 2008, we capitalized software development costs totaling $8.7 million, $5.6 million and $20.9 million, respectively. At December 31, 2010 and 2009, other assets included $28.1 million and $29.7 million of net capitalized software, respectively. During the years ended December 31, 2010, 2009 and 2008, we recognized amortization of capitalized software of $10.2 million, $11.5 million and $10.0 million, respectively, which is included in depreciation and amortization in our consolidated statements of operations.

During the year ended December 31, 2008, we reassessed our approach to communication technology needs at our properties, which resulted in the discontinuation of an infrastructure project and a $5.4 million write-off of related hardware and capitalized internal and consulting costs included in other assets. The write-off, which is net of sales proceeds, is included in other expenses, net. During the year ended December 31, 2008, we additionally recorded a $1.6 million write-off of certain software and hardware assets that are no longer consistent with our information technology strategy. This write-off is included in depreciation and amortization. There were no similar write-offs during the years ended December 31, 2010 or 2009.

Noncontrolling Interests

Effective January 1, 2009, we adopted the provisions of FASB Statement of Financial Accounting Standards No. 160, Noncontrolling Interests in Consolidated Financial Statements — an amendment of ARB No. 51, or SFAS 160, which are codified in FASB ASC Topic 810. These provisions clarified that a noncontrolling interest in a subsidiary is an ownership interest in a consolidated entity, which should be reported as equity in the parent’s consolidated financial statements. These provisions require disclosure, on the face of the consolidated statements of operations, of the amounts of consolidated net income (loss) and other comprehensive income (loss) attributable to controlling and noncontrolling interests, eliminating the past practice of reporting amounts of income attributable to noncontrolling interests as an adjustment in arriving at consolidated net income. These provisions also require us to attribute to noncontrolling interests their share of losses even if such attribution results in a deficit noncontrolling interest balance within our equity accounts, and in some instances, recognize a gain or loss in net income when a subsidiary is deconsolidated.

In connection with our retrospective application of these provisions, we reclassified into our consolidated equity accounts the historical balances related to noncontrolling interests in consolidated real estate partnerships and the portion of noncontrolling interests in the Aimco Operating Partnership related to the Aimco Operating Partnership’s common OP Units and High Performance Units. At December 31, 2008, the carrying amount of noncontrolling interests in consolidated real estate partnerships was $380.7 million and the carrying amount for noncontrolling interests in Aimco Operating Partnership attributable to common OP Units and High Performance Units was zero, due to cash distributions in excess of the positive balances related to those noncontrolling interests.

Noncontrolling Interests in Consolidated Real Estate Partnerships

We report the unaffiliated partners’ interests in our consolidated real estate partnerships as noncontrolling interests in consolidated real estate partnerships. Noncontrolling interests in consolidated real estate partnerships represent the noncontrolling partners’ share of the underlying net assets of our consolidated real estate partnerships. Prior to 2009, when these consolidated real estate partnerships made cash distributions to partners in excess of the carrying amount of the noncontrolling interest, we generally recorded a charge equal to the amount of such excess distribution, even though there was no economic effect or cost. These charges are reported in the consolidated statements of operations for the year ended December 31, 2008, within noncontrolling interests in consolidated real estate partnerships. Also prior to 2009, we allocated the noncontrolling partners’ share of partnership losses to noncontrolling partners to the extent of the carrying amount of the noncontrolling interest. We generally recorded a charge when the noncontrolling partners’ share of partnership losses exceeds the carrying amount of the noncontrolling interest, even though there is no economic effect or cost. These charges are reported in the consolidated statements of operations within noncontrolling interests in consolidated real estate partnerships. We did not record charges for distributions or losses in certain limited instances where the noncontrolling partner had a legal obligation and financial capacity to contribute additional capital to the partnership. For the year ended December 31, 2008, we recorded charges for partnership losses resulting from depreciation of approximately $9.0 million that were not allocated to noncontrolling partners because the losses exceeded the carrying amount of the noncontrolling interest.

Noncontrolling interests in consolidated real estate partnerships consist primarily of equity interests held by limited partners in consolidated real estate partnerships that have finite lives. The terms of the related partnership agreements generally require the partnership to be liquidated following the sale of the partnership’s real estate. As the general partner in these partnerships, we ordinarily control the execution of real estate sales and other events that could lead to the liquidation, redemption or other settlement of noncontrolling interests. The aggregate carrying amount of noncontrolling interests in consolidated real estate partnerships is approximately $291.5 million at December 31, 2010. The aggregate fair value of these interests varies based on the fair value of the real estate owned by the partnerships. Based on the number of classes of finite-life noncontrolling interests, the number of properties in which there is direct or indirect noncontrolling ownership, complexities in determining the allocation of liquidation proceeds among partners and other factors, we believe it is impracticable to determine the total required payments to the noncontrolling interests in an assumed liquidation at December 31, 2010. As a result of real estate depreciation that is recognized in our financial statements and appreciation in the fair value of real estate that is not recognized in our financial statements, we believe that the aggregate fair value of our noncontrolling interests exceeds their aggregate carrying amount. As a result of our ability to control real estate sales and other events that require payment of noncontrolling interests and our expectation that proceeds from real estate sales will be sufficient to liquidate related noncontrolling interests, we anticipate that the eventual liquidation of these noncontrolling interests will not have an adverse impact on our financial condition.

Changes in our ownership interest in consolidated real estate partnerships generally consist of our purchase of an additional interest in or the sale of our entire interest in a consolidated real estate partnership. The effect on our equity of our purchase of additional interests in consolidated real estate partnerships during the year ended December 31, 2010 is shown in the consolidated statement of equity and further discussed in Note 3. Our purchase of additional interests in consolidated real estate partnerships had no significant effect on our equity during the years ended December 31, 2009 and 2008. The effect on our equity of sales of our entire interest in consolidated real estate partnerships is reflected in our consolidated financial statements as sales of real estate and accordingly the effect on our equity is reflected as gains on disposition of real estate, less the amounts of such gains attributable to noncontrolling interests, within consolidated net (loss) income attributable to Aimco common stockholders.

Noncontrolling Interests in Aimco Operating Partnership

Noncontrolling interests in Aimco Operating Partnership consist of common OP Units, High Performance Units and preferred OP Units held by limited partners in the Aimco Operating Partnership other than Aimco. We allocate the Aimco Operating Partnership’s income or loss to the holders of common OP Units and High Performance Units based on the weighted average number of common partnership units (including those held by us) and High Performance Units outstanding during the period. During 2010, 2009 and 2008, the holders of common OP Units and equivalents had a weighted average ownership interest in the Aimco Operating Partnership of was approximately 7%, 7% and 10%, respectively. Holders of the preferred OP Units participate in the Aimco Operating Partnership’s income or loss only to the extent of their preferred distributions. See Note 10 for further information regarding noncontrolling interests in the Aimco Operating Partnership.

Revenue Recognition

Our properties have operating leases with apartment residents with terms averaging 12 months. We recognize rental revenue related to these leases, net of any concessions, on a straight-line basis over the term of the lease. We recognize revenues from property management, asset management, syndication and other services when the related fees are earned and are realized or realizable.

Advertising Costs

We generally expense all advertising costs as incurred to property operating expense. For the years ended December 31, 2010, 2009 and 2008, for both continuing and discontinued operations, total advertising expense was $14.2 million, $21.7 million and $31.8 million, respectively.

Insurance

We believe that our insurance coverages insure our properties adequately against the risk of loss attributable to fire, earthquake, hurricane, tornado, flood, and other perils. In addition, we have insurance coverage for substantial portions of our property, workers’ compensation, health, and general liability exposures. Losses are accrued based upon our estimates of the aggregate liability for uninsured losses incurred using certain actuarial assumptions followed in the insurance industry and based on our experience.

Stock-Based Compensation

We recognize all stock-based employee compensation, including grants of employee stock options, in the consolidated financial statements based on the grant date fair value and recognize compensation cost, which is net of estimates for expected forfeitures, ratably over the awards’ requisite service period. See Note 12 for further discussion of our stock-based compensation.

Tax Credit Arrangements

We sponsor certain partnerships that own and operate apartment properties that qualify for tax credits under Section 42 of the Internal Revenue Code of 1986, as amended, which we refer to as the Code, and for the U.S. Department of Housing and Urban Development, or HUD, subsidized rents under HUD’s Section 8 program. These partnerships acquire, develop and operate qualifying affordable housing properties and are structured to provide for the pass-through of tax credits and deductions to their partners. The tax credits are generally realized ratably over the first ten years of the tax credit arrangement and are subject to the partnership’s compliance with applicable laws and regulations for a period of 15 years. Typically, we are the general partner with a legal ownership interest of one percent or less. We market limited partner interests of at least 99 percent to unaffiliated institutional investors (which we refer to as tax credit investors or investors) and receive a syndication fee from each investor upon such investor’s admission to the partnership. At inception, each investor agrees to fund capital contributions to the partnerships. We agree to perform various services for the partnerships in exchange for fees over the expected duration of the tax credit service period. The related partnership agreements generally require adjustment of each tax credit investor’s required capital contributions if actual tax benefits to such investor differ from projected amounts.

We have determined that the partnerships in these arrangements are variable interest entities and, where we are general partner, we are generally the primary beneficiary that is required to consolidate the partnerships. When the contractual arrangements obligate us to deliver tax benefits to the investors, and entitle us through fee arrangements to receive substantially all available cash flow from the partnerships, we account for these partnerships as wholly owned subsidiaries. Capital contributions received by the partnerships from tax credit investors represent, in substance, consideration that we receive in exchange for our obligation to deliver tax credits and other tax benefits to the investors, and the receipts are recognized as revenue in our consolidated financial statements when our obligation to the investors is relieved upon delivery of the expected tax benefits.

In summary, our accounting treatment recognizes the income or loss generated by the underlying real estate based on our economic interest in the partnerships. Proceeds received in exchange for the transfer of the tax credits are recognized as revenue proportionately as the tax benefits are delivered to the tax credit investors and our obligation is relieved. Syndication fees and related costs are recognized in income upon completion of the syndication effort. We recognize syndication fees in amounts determined based on a market rate analysis of fees for comparable services, which generally fell within a range of 10% to 15% of investor contributions during the periods presented. Other direct and incremental costs incurred in structuring these arrangements are deferred and amortized over the expected duration of the arrangement in proportion to the recognition of related income. Investor contributions in excess of recognized revenue are reported as deferred income in our consolidated balance sheets.

During the year ended December 31, 2010, we recognized a net $1.0 million reduction of syndication fees due to our determination that certain syndication fees receivable were uncollectible. We recognized no syndication fee income during the year ended December 31, 2009. During the year ended December 31, 2008, we recognized syndication fee income of $3.4 million. During the years ended December 31, 2010, 2009 and 2008 we recognized revenue associated with the delivery of tax benefits of $28.9 million, $36.6 million and $29.4 million, respectively. At December 31, 2010 and 2009, $114.7 million and $148.1 million, respectively, of investor contributions in excess of the recognized revenue were included in deferred income in our consolidated balance sheets.

Discontinued Operations

We classify certain properties and related assets and liabilities as held for sale when they meet certain criteria. The operating results of such properties as well as those properties sold during the periods presented are included in discontinued operations in both current periods and all comparable periods presented. Depreciation is not recorded on properties once they have been classified as held for sale; however, depreciation expense recorded prior to classification as held for sale is included in discontinued operations. The net gain on sale and any impairment losses are presented in discontinued operations when recognized. See Note 13 for additional information regarding discontinued operations.

Derivative Financial Instruments

We primarily use long-term, fixed-rate and self-amortizing non-recourse debt to avoid, among other things, risk related to fluctuating interest rates. For our variable rate debt, we are sometimes required by our lenders to limit our exposure to interest rate fluctuations by entering into interest rate swap or cap agreements. The interest rate swap agreements moderate our exposure to interest rate risk by effectively converting the interest on variable rate debt to a fixed rate. The interest rate cap agreements effectively limit our exposure to interest rate risk by providing a ceiling on the underlying variable interest rate. The fair values of the interest rate swaps are reflected as assets or liabilities in the balance sheet, and periodic changes in fair value are included in interest expense or equity, as appropriate. The interest rate caps are not material to our financial position or results of operations.

As of December 31, 2010 and 2009, we had interest rate swaps with aggregate notional amounts of $52.3 million, and recorded fair values of $2.7 million and $1.6 million, respectively, reflected in accrued liabilities and other in our consolidated balance sheets. At December 31, 2010, these interest rate swaps had a weighted average term of 10.1 years. We have designated these interest rate swaps as cash flow hedges and recognize any changes in their fair value as an adjustment of accumulated other comprehensive income (loss) within equity to the extent of their effectiveness. Changes in the fair value of these instruments and the related amounts of such changes that were reflected as an adjustment of accumulated other comprehensive loss within equity and as an adjustment of earnings (ineffectiveness) are discussed in the foregoing Fair Value Measurements section.

If the forward rates at December 31, 2010 remain constant, we estimate that during the next twelve months, we would reclassify into earnings approximately $1.6 million of the unrealized losses in accumulated other comprehensive loss. If market interest rates increase above the 3.43% weighted average fixed rate under these interest rate swaps we will benefit from net cash payments due to us from our counterparty to the interest rate swaps.

We have entered into total rate of return swaps on various fixed-rate secured tax-exempt bonds payable and fixed-rate notes payable to convert these borrowings from a fixed rate to a variable rate and provide an efficient financing product to lower our cost of borrowing. In exchange for our receipt of a fixed rate generally equal to the underlying borrowing’s interest rate, the total rate of return swaps require that we pay a variable rate, equivalent to the Securities Industry and Financial Markets Association Municipal Swap Index, or SIFMA, rate for tax-exempt bonds payable and the 30-day LIBOR rate for notes payable, plus a risk spread. These swaps generally have a second or third lien on the property collateralized by the related borrowings and the obligations under certain of these swaps are cross-collateralized with certain of the other swaps with a particular counterparty. The underlying borrowings are generally callable at our option, with no prepayment penalty, with 30 days advance notice, and the swaps generally have a term of less than five years. The total rate of return swaps have a contractually defined termination value generally equal to the difference between the fair value and the counterparty’s purchased value of the underlying borrowings, which may require payment by us or to us for such difference. Accordingly, we believe fluctuations in the fair value of the borrowings from the inception of the hedging relationship generally will be offset by a corresponding fluctuation in the fair value of the total rate of return swaps.

We designate total rate of return swaps as hedges of the risk of overall changes in the fair value of the underlying borrowings. At each reporting period, we estimate the fair value of these borrowings and the total rate of return swaps and recognize any changes therein as an adjustment of interest expense. We evaluate the effectiveness of these fair value hedges at the end of each reporting period and recognize an adjustment of interest expense as a result of any ineffectiveness.

Borrowings payable subject to total rate of return swaps with aggregate outstanding principal balances of $276.9 million and $352.7 million at December 31, 2010 and 2009, respectively, are reflected as variable rate borrowings in Note 6. Due to changes in the estimated fair values of these debt instruments and the corresponding total rate of return swaps, we increased the carrying amount of property loans payable by $4.8 million and $5.2 million for the years ended December 31, 2010 and 2009, respectively, and reduced the carrying amount of property loans payable by $20.1 million for the year ended December 31, 2008, with offsetting adjustments to the swap values in accrued liabilities, resulting in no net effect on net income. Refer to the foregoing Fair Value Measurements section for further discussion of fair value measurements related to these arrangements. During 2010, 2009 and 2008, we determined these hedges were fully effective and accordingly we made no adjustments to interest expense for ineffectiveness.

At December 31, 2010, the weighted average fixed receive rate under the total return swaps was 6.8% and the weighted average variable pay rate was 1.6%, based on the applicable SIFMA and 30-day LIBOR rates effective as of that date. Further information related to our total return swaps as of December 31, 2010 is as follows (dollars in millions):


				Weighted
		Year of		Average					Year of		Weighted Average Swap
		Debt		Debt Interest			Swap Notional		Swap		Variable Pay Rate at
Debt Principal		Maturity		Rate			Amount		Maturity		December 31, 2010
$	29.2		2012		7.5	%	$	29.2		2012	1.6%
	24.0		2015		6.9	%		24.0		2012	1.1%
	93.0		2031		7.4	%		93.0		2012	1.1%
	106.1		2036		6.2	%		106.5		2012	2.2%
	12.1		2038		5.5	%		12.1		2012	1.0%
	12.5		2048		6.5	%		12.5		2012	1.0%

$	276.9						$	277.3

Fair Value Measurements

Beginning in 2008, we applied the FASB’s revised accounting provisions related to fair value measurements, which are codified in FASB ASC Topic 820. These revised provisions define fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, establish a hierarchy that prioritizes the information used in developing fair value estimates and require disclosure of fair value measurements by level within the fair value hierarchy. The hierarchy gives the highest priority to quoted prices in active markets (Level 1 measurements) and the lowest priority to unobservable data (Level 3 measurements), such as the reporting entity’s own data. We adopted the revised fair value measurement provisions that apply to recurring and nonrecurring fair value measurements of financial assets and liabilities effective January 1, 2008, and the provisions that apply to the remaining fair value measurements effective January 1, 2009, and at those times determined no transition adjustments were required.

The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date and includes three levels defined as follows:

	Level 1 —		Unadjusted quoted prices for identical and unrestricted assets or liabilities in active markets

	Level 2 —		Quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument

	Level 3 —		Unobservable inputs that are significant to the fair value measurement

A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement.

Following are descriptions of the valuation methodologies used for our significant assets or liabilities measured at fair value on a recurring or nonrecurring basis. Although some of the valuation methodologies use observable market inputs in limited instances, the majority of inputs we use are unobservable and are therefore classified within Level 3 of the valuation hierarchy.

Real Estate

From time to time, we may be required to recognize an impairment loss to the extent the carrying amount of a property exceeds the estimated fair value, for properties classified as held for use, or the estimated fair value, less estimated selling costs, for properties classified as held for sale. Additionally, we are generally required to initially measure real estate recognized in connection with our consolidation of real estate partnerships at fair value.

We estimate the fair value of real estate using income and market valuation techniques using information such as broker estimates, purchase prices for recent transactions on comparable assets and net operating income capitalization analyses using observable and unobservable inputs such as capitalization rates, asset quality grading, geographic location analysis, and local supply and demand observations. For certain properties classified as held for sale, we may also recognize the impairment loss based on the contract sale price, which we believe is representative of fair value, less estimated selling costs.

Notes Receivable

We assess the collectibility of notes receivable on a periodic basis, which assessment consists primarily of an evaluation of cash flow projections of the borrower to determine whether estimated cash flows are sufficient to repay principal and interest in accordance with the contractual terms of the note. We recognize impairments on notes receivable when it is probable that principal and interest will not be received in accordance with the contractual terms of the loan. The amount of the impairment to be recognized generally is based on the fair value of the real estate, which represents the primary source of loan repayment. The fair value of real estate is estimated through income and market valuation approaches using information such as broker estimates, purchase prices for recent transactions on comparable assets and net operating income capitalization analyses using observable and unobservable inputs such as capitalization rates, asset quality grading, geographic location analysis, and local supply and demand observations.

Interest Rate Swaps

We recognized interest rate swaps at their estimated fair value. We estimate the fair value of interest rate swaps using an income approach with primarily observable inputs, including information regarding the hedged variable cash flows and forward yield curves relating to the variable interest rates on which the hedged cash flows are based.

Total Rate of Return Swaps

Our total rate of return swaps have contractually-defined termination values generally equal to the difference between the fair value and the counterparty’s purchased value of the underlying borrowings. Upon termination, we are required to pay the counterparty the difference if the fair value is less than the purchased value, and the counterparty is required to pay us the difference if the fair value is greater than the purchased value. The underlying borrowings are generally callable, at our option, at face value prior to maturity and with no prepayment penalty. Due to our control of the call features in the underlying borrowings, we believe the inherent value of any differential between the fixed and variable cash payments due under the swaps would be significantly discounted by a market participant willing to purchase or assume any rights and obligations under these contracts.

The swaps are generally cross-collateralized with other swap contracts with the same counterparty and do not allow transfer or assignment, thus there is no alternate or secondary market for these instruments. Accordingly, our assumptions about the fair value that a willing market participant would assign in valuing these instruments are based on a hypothetical market in which the highest and best use of these contracts is in-use in combination with the related borrowings, similar to how we use the contracts. Based on these assumptions, we believe the termination value, or exit value, of the swaps approximates the fair value that would be assigned by a willing market participant. We calculate the termination value using a market approach by reference to estimates of the fair value of the underlying borrowings, which are discussed below, and an evaluation of potential changes in the credit quality of the counterparties to these arrangements. We compare our estimates of the fair value of the swaps and related borrowings to the valuations provided by the counterparties on a quarterly basis.

Non-recourse Property Debt

We recognize changes in the fair value of the non-recourse property debt subject to total rate of return swaps discussed above, which we have designated as fair value hedges. Additionally, we are generally required to initially measure non-recourse property debt recognized in connection with our consolidation of real estate partnerships at fair value.

We estimate the fair value of debt instruments using an income and market approach, including comparison of the contractual terms to observable and unobservable inputs such as market interest rate risk spreads, collateral quality and loan-to-value ratios on similarly encumbered assets within our portfolio. These borrowings are collateralized and non-recourse to us; therefore, we believe changes in our credit rating will not materially affect a market participant’s estimate of the borrowings’ fair value.

The methods described above may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, although we believe our valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain assets and liabilities could result in a different estimate of fair value at the reporting date.

The table below presents amounts at December 31, 2010, 2009 and 2008 (and the changes in fair value between such dates) for significant items measured in our consolidated balance sheets at fair value on a recurring basis (in thousands). Certain of these fair value measurements are based on significant unobservable inputs classified within Level 3 of the valuation hierarchy. When a determination is made to classify a fair value measurement within Level 3 of the valuation hierarchy, the determination is based upon the significance of the unobservable factors to the overall fair value measurement. However, Level 3 fair value measurements typically include, in addition to the unobservable or Level 3 components, observable components that can be validated to observable external sources; accordingly, the changes in fair value in the table below are due in part to observable factors that are part of the valuation methodology.


	Level 2			Level 3
							Changes in Fair
							Value of Debt
							Subject to Total
	Interest Rate			Total Rate of			Rate of Return
	Swaps			Return Swaps			Swaps			Total
Fair value at December 31, 2008	$	(2,557	)	$	(29,495	)	$	29,495		$	(2,557	)
Unrealized gains (losses) included in earnings (1)(2)		(447	)		5,188			(5,188	)		(447	)
Realized gains (losses) included in earnings		—			—			—			—
Unrealized gains (losses) included in equity		1,408			—			—			1,408

Fair value at December 31, 2009	$	(1,596	)	$	(24,307	)	$	24,307		$	(1,596	)
Unrealized gains (losses) included in earnings (1)(2)		(45	)		4,765			(4,765	)		(45	)
Realized gains (losses) included in earnings		—			—			—			—
Unrealized gains (losses) included in equity		(1,105	)		—			—			(1,105	)

Fair value at December 31, 2010	$	(2,746	)	$	(19,542	)	$	19,542		$	(2,746	)


(1)		Unrealized gains (losses) relate to periodic revaluations of fair value and have not resulted from the settlement of a swap position.

(2)		Included in interest expense in the accompanying consolidated statements of operations.

The table below presents information regarding significant amounts measured at fair value in our consolidated financial statements on a nonrecurring basis during the years ended December 31, 2010 and 2009, all of which were based, in part, on significant unobservable inputs classified within Level 3 of the valuation hierarchy (in thousands):


	2010					2009
	Fair Value					Fair Value
	Measurement		Gain (loss)			Measurement		Gain (loss)
Real estate (impairment losses) (1)	$	62,111	$	(12,043	)	$	425,345	$	(48,542	)
Real estate (newly consolidated) (2)		117,083		1,104			10,798		—
Property debt (newly consolidated) (2)		83,890		—			2,031		—
Investment in Casden Properties LLC (Note 5)		—		—			10,000		(20,740	)


(1)		During the year ended December 31, 2010 and 2009, we reduced the aggregate carrying amounts of $74.2 million and $473.9 million, respectively, for real estate assets classified as held for sale to their estimated fair value, less estimated costs to sell. These impairment losses recognized generally resulted from a reduction in the estimated holding period for these assets. In periods prior to their classification as held for sale, we evaluated the recoverability of their carrying amounts based on an analysis of the undiscounted cash flows over the then anticipated holding period.

(2)		In connection with our adoption of ASU 2009-17 (see preceding discussion of Variable Interest Entities) and reconsideration events during the year ended December 31, 2010, we consolidated 17 partnerships at fair value. With the exception of such partnerships’ investments in real estate properties and related non-recourse property debt obligations, we determined the carrying amounts of the related assets and liabilities approximated their fair values. The difference between our recorded investments in such partnerships and the fair value of the assets and liabilities recognized in consolidation, resulted in an adjustment of consolidated equity (allocated between Aimco and noncontrolling interests) for those partnerships consolidated in connection with our adoption of ASU 2009-17. For the partnerships we consolidated at fair value due to reconsideration events during the year ended December 31, 2010, the difference between our recorded investments in such partnerships and the fair value of the assets, liabilities and noncontrolling interests recognized upon consolidation resulted in our recognition of a gain, which is included in gain on disposition of unconsolidated real estate and other in our consolidated statement of operations for the year ended December 31, 2010. We recognized no similar gain as a result of our consolidation of partnerships during the year ended December 31, 2009.

Disclosures Regarding Fair Value of Financial Instruments

We believe that the aggregate fair value of our cash and cash equivalents, receivables, payables and short-term secured debt approximates their aggregate carrying value at December 31, 2010, due to their relatively short-term nature and high probability of realization. We estimate fair value for our notes receivable and debt instruments as discussed in the preceding Fair Value Measurements section The estimated aggregate fair value of our notes receivable was approximately $126.0 million and $126.1 million at December 31, 2010 and 2009, respectively, as compared to carrying amounts of $137.6 million and $139.6 million, respectively. See Note 5 for further information on notes receivable. The estimated aggregate fair value of our consolidated debt (including amounts reported in liabilities related to assets held for sale) was approximately $5.6 billion and $5.7 billion at December 31, 2010 and 2009, respectively, as compared to the carrying amounts of $5.5 billion and $5.7 billion, respectively. See Note 6 and Note 7 for further details on our consolidated debt. Refer to Derivative Financial Instruments for further discussion regarding certain of our fixed rate debt that is subject to total rate of return swap instruments.

Income Taxes

We have elected to be taxed as a REIT under the Code commencing with our taxable year ended December 31, 1994, and intend to continue to operate in such a manner. Our current and continuing qualification as a REIT depends on our ability to meet the various requirements imposed by the Code, which are related to organizational structure, distribution levels, diversity of stock ownership and certain restrictions with regard to owned assets and categories of income. If we qualify for taxation as a REIT, we will generally not be subject to United States Federal corporate income tax on our taxable income that is currently distributed to stockholders. This treatment substantially eliminates the “double taxation” (at the corporate and stockholder levels) that generally results from an investment in a corporation.

Even if we qualify as a REIT, we may be subject to United States Federal income and excise taxes in various situations, such as on our undistributed income. We also will be required to pay a 100% tax on any net income on non-arms length transactions between us and a TRS (described below) and on any net income from sales of property that was property held for sale to customers in the ordinary course. We and our stockholders may be subject to state or local taxation in various state or local jurisdictions, including those in which we transact business or our stockholders reside. In addition, we could also be subject to the alternative minimum tax, or AMT, on our items of tax preference. The state and local tax laws may not conform to the United States Federal income tax treatment. Any taxes imposed on us reduce our operating cash flow and net income.

Certain of our operations or a portion thereof, including property management, asset management and risk management, are conducted through taxable REIT subsidiaries, which are subsidiaries of the Aimco Operating Partnership, and each of which we refer to as a TRS. A TRS is a C-corporation that has not elected REIT status and as such is subject to United States Federal corporate income tax. We use TRS entities to facilitate our ability to offer certain services and activities to our residents and investment partners that cannot be offered directly by a REIT. We also use TRS entities to hold investments in certain properties.

For our TRS entities, deferred income taxes result from temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for Federal income tax purposes, and are measured using the enacted tax rates and laws that are expected to be in effect when the differences reverse. We reduce deferred tax assets by recording a valuation allowance when we determine based on available evidence that it is more likely than not that the assets will not be realized. We recognize the tax consequences associated with intercompany transfers between the REIT and TRS entities when the related assets are sold to third parties, impaired or otherwise disposed of for financial reporting purposes.

In March 2008, we were notified by the Internal Revenue Service that it intended to examine the 2006 Federal tax return for the Aimco Operating Partnership. During June 2008, the IRS issued AIMCO-GP, Inc., the general and tax matters partner of the Aimco Operating Partnership, a summary report including the IRS’s proposed adjustments to the Aimco Operating Partnership’s 2006 Federal tax return. In addition, in May 2009, we were notified by the IRS that it intended to examine the 2007 Federal tax return for the Aimco Operating Partnership. During November 2009, the IRS issued AIMCO-GP, Inc. a summary report including the IRS’s proposed adjustments to the Aimco Operating Partnership’s 2007 Federal tax return. The matter is currently pending administratively before IRS Appeals and the IRS has made no determination. We do not expect the 2006 or 2007 proposed adjustments to have any material effect on our unrecognized tax benefits, financial condition or results of operations.

Concentration of Credit Risk

Financial instruments that potentially could subject us to significant concentrations of credit risk consist principally of notes receivable and total rate of return swaps. Approximately $89.3 million of our notes receivable, or 1.2% of the carrying amount of our total assets, at December 31, 2010, are collateralized by 84 buildings with 1,596 residential units in the West Harlem area of New York City. There are no other significant concentrations of credit risk with respect to our notes receivable due to the large number of partnerships that are borrowers under the notes and the geographic diversification of the properties that serve as the primary source of repayment of the notes.

At December 31, 2010, we had total rate of return swap positions with two financial institutions totaling $277.3 million. We periodically evaluate counterparty credit risk associated with these arrangements. At the current time, we have concluded we do not have material exposure. In the event either counterparty were to default under these arrangements, loss of the net interest benefit we generally receive under these arrangements, which is equal to the difference between the fixed rate we receive and the variable rate we pay, may adversely impact our results of operations and operating cash flows.

Comprehensive Income or Loss

As discussed in the Derivative Financial Instruments section, we recognize changes in the fair value of our cash flow hedges as changes in accumulated other comprehensive loss within equity. For the years ended December 31, 2010 and 2009, before the effects of noncontrolling interests, our consolidated comprehensive loss totaled $90.7 million and $43.4 million, respectively, and for the year ended December 31, 2008, our consolidated comprehensive income totaled $624.9 million.

Earnings per Share

We calculate earnings per share based on the weighted average number of shares of Common Stock, common stock equivalents, participating securities and other potentially dilutive securities outstanding during the period (see Note 14).

Use of Estimates

The preparation of our consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts included in the financial statements and accompanying notes thereto. Actual results could differ from those estimates.

Reclassifications and Adjustments

Certain items included in the 2009 and 2008 financial statements have been reclassified to conform to the current presentation, including adjustments for discontinued operations.

During the three months ended March 31, 2010, we reduced the investment and noncontrolling interest balances for certain of our consolidated partnerships by $38.7 million related to excess amounts allocated to the investments upon our consolidation of such partnerships.