UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

Form 10-K

(Mark One)

[X] ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2010

[ ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from _________to _________

Commission file number 0-10412

NATIONAL PROPERTY INVESTORS 4

(Exact name of registrant as specified in its charter)

California	13-3031722
(State or other jurisdiction of	(I.R.S. Employer
incorporation or organization)	Identification No.)

55 Beattie Place, PO Box 1089

Greenville, South Carolina 29602

(Address of principal executive offices)

Registrant's telephone number, including area code (864) 239-1000

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

None

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

Units of Limited Partnership Interest

(Title of class)

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

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Exchange 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 [ ] No

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (section 229.405 of this chapter) is not contained herein, and willnot be contained, to the best of the 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. [X]

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.

Large accelerated filer£	Accelerated filer£
Non-accelerated filer£(Do not check if a smaller reporting company)	Smaller reporting companyS

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

State the aggregate market value of the voting and non-voting partnership interests held by non-affiliates computed by reference to the price at which the partnership interests were last sold, or the average bid and asked price of such partnership interests as of the last business day of the registrant’s most recently completed second fiscal quarter. No market exists for the limited partnership interests of the Registrant, and, therefore, no aggregate market value can be determined.

DOCUMENTS INCORPORATED BY REFERENCE

None

FORWARD-LOOKING STATEMENTS

The Private Securities Litigation Reform Act of 1995 provides a “safe harbor” for forward-looking statements in certain circumstances. Certain information included in this Annual Report contains or may contain information that is forward-looking within the meaning of the federal securities laws, including, without limitation, statements regarding the Partnership’s ability to maintain current or meet projected occupancy, rental rates and property operating results and the effect of redevelopments. Actual results may differ materially from those described in these forward-looking statements and, in addition, will be affected by a variety of risks and factors, some of which are beyond the Partnership’s control, including, without limitation: financing risks, including the availability and cost of financing and the risk that the Partnership’s cash flows from operations may be insufficient to meet required payments of principal and interest; natural disasters and severe weather such as hurricanes; national and local economic conditions, including the pace of job growth and the level of unemployment; energy costs; the terms of governmental regulations that affect the Partnership’s property and interpretations of those regulations; the competitive environment in which the Partnership operates; real estate risks, including fluctuations inreal estate values and the general economic climate in local markets and competition for residents in such markets; insurance risk, including the cost of insurance; litigation, including costs associated with prosecuting or defending claims and any adverse outcomes; and possible environmental liabilities, including costs, fines or penalties that may be incurred due to necessary remediation of contamination of properties presently owned or previously owned by the Partnership. Readers should carefully review the Partnership’s financial statements and the notes thereto, as well as the other documents the Partnership files from time to time with the Securities and Exchange Commission.

PART I

Item 1. Business

National Property Investors 4 (the "Partnership" or "Registrant") is a California limited partnership formed in July 1980. The Partnership is engaged in the business of operating and holding real estate properties for investment. NPI Equity Investments, Inc., a Florida corporation, became the Registrant's managing general partner (the "Managing General Partner") on June 21, 1991. The Managing General Partner was a subsidiary of National Property Investors, Inc. until December 31, 1996, at which time Insignia Properties Trust ("IPT") acquired the stock of theManaging General Partner. On October 1, 1998, IPT merged into Apartment Investment and Management Company ("AIMCO"), a publicly traded real estate investment trust. Therefore, the Managing General Partner is a wholly-owned subsidiary of AIMCO. The Partnership Agreement provides that the Partnership is to terminate on December 31, 2022, unless terminated prior to such date.

The principal business of the Partnership is to hold for investment and ultimately sell income-producing multi-family residential properties. The Partnership is a "closed" limited partnership real estate syndicate formed to acquire multi-family residential properties. In 1981, the Partnership offered, pursuant to a registration statement filed with the Securities Exchange Commission, 70,000 Limited Partnership units (the "Units") and sold 60,005 Units aggregating $30,002,500. The net proceeds of the offering were used to acquire seven income-producing residential properties. The Partnership's original property portfolio was geographically diversified. The Partnership's acquisition activities were completed in May 1982 and since then the principal activity of the Partnership has been managing its portfolio. Six of the properties were sold prior to 1997. The Partnership currently owns one residential property (see "Item 2. Property"). Since its initial offering the Partnership has not received, nor are the Limited Partners required to make, additional capital contributions.

The Partnership has no employees. Management and administrative services are provided by the Managing General Partner and by agents retained by the Managing General Partner. Property management services are provided by an affiliate of the Managing General Partner.

A further description of the Partnership's business is included in "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations" included in this Form 10-K.

Item 2. Property

The following table sets forth the Partnership's investment in its property:

	Date of
Property	Purchase	Type of Ownership	Use

Villageof PennbrookApartments	12/15/81	Fee simple, subject to	Apartment
Falls Township, Pennsylvania		first, second and third	722 units
		mortgages

Schedule of Property

Set forth below for the Partnership's property is the gross carrying value, accumulated depreciation, depreciable life, method of depreciation, and Federal tax basis.

	Gross
	Carrying	Accumulated	Depreciable	Method of	Federal
Property	Value	Depreciation	Life	Depreciation	Tax Basis
Village of	(in thousands)				(in thousands)
Pennbrook
Apartments	$42,289	$33,705	5-30 yrs	S/L	$ 9,310

See “Note A – Organization and Summary of Significant Accounting Policies” to the financial statements included in "Item 8. Financial Statements and Supplementary Data" for a description of the Partnership's capitalization and depreciation policies.

Schedule of Property Indebtedness

The following table sets forth certain information relating to the fixed rate loans encumbering the Partnership's property.

	Principal				Principal
	Balance at	Stated			Balance
	December 31,	Interest	Period	Maturity	Due at
Property	2010	Rate (1)	Amortized	Date	Maturity (2)
	(in thousands)			(in thousands)
Villageof Pennbrook
Apartments
1^st mortgage	$25,061	7.06%	30 yrs	09/01/21	$19,515
2^nd mortgage	13,030	6.32%	30 yrs	09/01/21	10,561
3^rd mortgage	9,713	6.62%	30 yrs	09/01/21	7,783
	$47,804				$37,859

(1) Fixed rate mortgages.

(2) See “Note C – Mortgage Notes Payable” to the financial statements included in “Item 8. Financial Statements and Supplementary Data” for information with respect to the Partnership’s ability to prepay these loans and other details about the loans.

Schedule of Rental Rates and Occupancy

Average annual rental rates and occupancy for 2010 and 2009 for the property are as follows:

	Average Annual
	Rental Rates		Average Annual
	(per unit)		Occupancy
Property	2010	2009	2010	2009
Villageof Pennbrook
Apartments	$11,385	$11,812	96%	92%

The Managing General Partner attributes the increase in occupancy at Village of Pennbrook Apartments to competitive pricing.

The real estate industry is highly competitive. The Partnership's property is subject to competition from other residential apartment complexes in the area. The Managing General Partner believes that the property is adequately insured. The property is an apartment complex which leases units for terms of one year or less. No tenant leases 10% or more of the available rental space. The property is in good physical condition, subject to normal depreciation and deterioration as is typical for assets of this type and age.

Schedule of Real Estate Taxes and Rate

Real estate taxes and rate in 2010 for the property were as follows:

	2010	2010
	Billing (1)	Rate
	(in thousands)
Villageof Pennbrook
Apartments	$760	17.59%

(1) The Partnership has a different fiscal year than the property’s real estate tax year.

Capital Improvements

During the year ended December 31, 2010, the Partnership completed approximately $617,000 of capital improvements at Village of Pennbrook Apartments, consisting primarily of construction related to the casualties discussed in “Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations”, building improvements and appliance, water heater, air conditioning unit and floor covering replacements. These improvements were funded from operating cash flow and insurance proceeds. The Partnership regularly evaluates the capital improvement needs of the property. While the Partnership has no material commitments for property improvements and replacements, certain routine capital expenditures are anticipated during 2011. Such capital expenditures will depend onthe physical condition of the property as well as anticipated cash flow generated by the property.

Capital expenditures will be incurred only if cash is available from operations, Partnership reserves or advances from AIMCO Properties, L.P., although AIMCO Properties, L.P. does not have an obligation to fund such advances. To the extent that capital improvements are completed, the Partnership’s distributable cash flow, if any, may be adversely affected at least in the short term.

Item 3. Legal Proceedings

As previously disclosed, AIMCO Properties, L.P. and NHP Management Company, both affiliates of the Managing General Partner, were defendants in a lawsuit, filed as a collective action in August 2003 in the United States District Court for the District of Columbia, alleging that they willfully violated the Fair Labor Standards Act (“FLSA”) by failing to pay maintenance workers overtime for time worked in excess of 40 hours per week (“overtime claims”). The plaintiffs also contended that AIMCO Properties, L.P. and NHP Management Company (“the Defendants”) failed to compensate maintenance workers for time that they were required to be "on-call" (“on-call claims”). In March 2007, the court in the District of Columbia decertified the collective action. In July 2007, plaintiffs’ counsel filed individual cases in Federal court in 22 jurisdictions. In the second quarter of 2008, AIMCO Properties, L.P. settled the overtime cases involving 652 plaintiffs and established a framework for resolving the 88 remaining “on-call” claims and the attorneys’ fees claimed by plaintiffs’ counsel. As a result, the lawsuits asserted in the 22 Federal courts were dismissed. During the fourth quarter of 2008, the settlement amounts for alleged unpaid overtime to employees were paid by those partnerships where the respective employees had worked. The Partnership was not required to pay any settlement amounts. During January 2011, the parties reached an agreement to settle the remaining “on-call claims” and the plaintiffs’ attorneys’ fees. The Partnership will not be required to pay any settlement amounts or plaintiffs’ attorneys’ fees as a result of this agreement. These settlements resolve the case in its entirety.

PART II

Item 5. Market for the Registrant's Common Equity, Related Security Holder Matters and Issuer Purchases of Equity Securities

The Partnership, a publicly-held limited partnership, offered 70,000 and sold 60,005 limited partnership units (the “Units”) aggregating $30,002,500. As of December 31, 2010, the Partnership had 60,005 Units outstanding held by 869 limited partners of record. Affiliates of the Managing General Partner owned 47,850 Units or 79.74% at December 31, 2010. No public trading market has developed for the Units, and it is not anticipated that such a market will develop in the future.

The Partnership distributed the following amounts during the years ended December 31, 2010 and 2009 (in thousands, except per unit data):

	Year Ended	Per Limited	Year Ended	Per Limited
	December 31,	Partnership	December 31,	Partnership
	2010	Unit	2009	Unit

Operations	$ --	$ --	$ 575	$ 9.48

Future cash distributions will depend on the levels of net cash generated from operations, the timing of the debt maturities, property sale and/or refinancings. The Partnership's cash available for distribution is reviewed on a monthly basis. There can be no assurance, however, that the Partnership will generate sufficient funds from operations after required capital improvement expenditures and repayment of amounts due to affiliates to permit distributions to its partners in 2011 or subsequent periods. See “Item 2. Property – Capital Improvements” for information relating to anticipated capital expenditures at the property.

In addition to its indirect ownership of the general partner interest in the Partnership, AIMCO and its affiliates owned 47,850 Units in the Partnership representing 79.74% of the outstanding Units at December 31, 2010. A number of these Units were acquired pursuant to tender offers made by AIMCO or its affiliates. It is possible that AIMCO or its affiliates will acquire additional Units in exchange for cash or a combination of cash and units in AIMCO Properties, L.P., the operating partnership of AIMCO, either through private purchases or tender offers. Pursuant to the Partnership Agreement, unitholders holding a majority of the Units are entitled to take action with respect to a variety of matters that include, but are not limited to, voting on certain amendments to the Partnership Agreement and voting to remove the Managing General Partner. As a result of its ownership of 79.74% of the outstanding Units, AIMCO is in a position to influence all such voting decisions with respect to the Partnership. With respect to 26,466 Units, AIMCO IPLP, L.P., an affiliate of AIMCO, is required to vote such Units: (i) against any increase in compensation payable to the Managing General Partner or to affiliates; and (ii) on all other matters submitted by it or its affiliates, in proportion to the votes cast by non-tendering unitholders. Except for the foregoing, no other limitations are imposed on AIMCO's or AIMCO IPLP, L.P.'s ability to influence voting decisions with respect to the Partnership. Although the Managing General Partner owes fiduciary duties to the limited partners of the Partnership, the Managing General Partner also owes fiduciary duties to AIMCO as its sole stockholder. As a result, the duties of the Managing General Partner, as managing general partner, to the Partnership and its limited partners may come into conflict with the duties of the Managing General Partner to AIMCO as its sole stockholder.

Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations

This item should be read in conjunction with the financial statements and other items contained elsewhere in this report.

The Partnership’s financial results depend upon a number of factors including the ability to attract and maintain tenants at the investment property, interest rates on mortgage loans, costs incurred to operate the investment property, general economic conditions and weather. As part of the ongoing business plan of the Partnership, the Managing General Partner monitors the rental market environment of its investment property to assess the feasibility of increasing rents, maintaining or increasing occupancy levels and protecting the Partnership from increases in expenses. As part of this plan, the Managing General Partner attempts to protect the Partnership from the burden of inflation-related increases in expenses by increasing rents and maintaining a high overall occupancy level. However, the Managing General Partner may use rental concessions and rental rate reductions to offset softening market conditions; accordingly, there is no guarantee that the Managing General Partner will be able to sustain such a plan. Further, a number of factors that are outside the control of the Partnership such as the local economic climate and weather can adversely or positively affect the Partnership’s financial results.

Results of Operations

The Partnership’s net loss for the years ended December 31, 2010 and 2009 was approximately $241,000 and $284,000, respectively. The decrease in net loss is due to increases in total revenues and casualty gain, partially offset by an increase in total expenses.

Total revenues increased due to an increase in rental income, partially offset by a decrease in other income. The increase in rental income is due to an increase in occupancy and a decrease in bad debt expense, partially offset by a decrease in the average rental rates at the Partnership’s investment property. Other income decreased due to decreases in tenant utility reimbursements, lease cancellation fees, late fees, application fees and ancillary services income at the Partnership’s investment property.

In February 2010, the Partnership’s property experienced damages from a snow storm of approximately $11,000. During the year ended December 31, 2010, the Partnership received insurance proceeds of approximately $9,000. The Partnership recognized a casualty gain of approximately $9,000 during the year ended December 31, 2010 as the associated assets were fully depreciated.

In April 2010, the Partnership’s property experienced damages from a fire. The estimated damages were approximately $44,000. During the year ended December 31, 2010, the Partnership received insurance proceeds of approximately $37,000 to cover the damages. After writing off the fully depreciated cost of the damaged assets, the Partnership recognized a casualty gain of approximately $37,000 during the year ended December 31, 2010.

In February 2009, Village of Pennbrook Apartments incurred damages as a result of heavy rain. The property suffered damages of approximately $15,000. Insurance proceeds of approximately $15,000 were received during the year ended December 31, 2009 to cover the damages. After writing off the fully depreciated cost of the damaged assets, the Partnership recognized a casualty gain of approximately $15,000 for the year ended December 31, 2009.

Total expenses increased due to increases in operating, depreciation and property tax expenses, partially offset by decreases in interest and general andadministrative expenses. Operating expenses increased due to increases in utilities and snow removal costs due to excessive snowfall in the area, partially offset by decreases in interior painting, painting supplies, salaries and benefits and resident eviction costs. Depreciation expense increased due to property improvements and replacements placed into service during the past twelve months which are now being depreciated. Property tax expense increased due to an increase in the tax rate at the Partnership’s investment property. Interest expense decreased due to scheduled payments on the mortgages encumbering the Partnership’s investment property and the payment of interest incurred in connection with the escheatment of unclaimed distributions during 2009, partially offset by an increase in interest on advances from AIMCO Properties, L.P.

General and administrative expenses decreased primarily due to a decrease in the partnership management fees paid during 2009 to affiliates of theManaging General Partnerfrom distributions from operations. Also included in general and administrative expenses for the years ended December 31, 2010 and 2009 are reimbursements to theManaging General Partneras allowed under the Partnership Agreement, costs associated with the quarterly and annual communications with investors and regulatory agencies and the annual audit required by the Partnership Agreement.

Liquidity and Capital Resources

At December 31, 2010, the Partnership had cash and cash equivalents of approximately $187,000, compared to approximately $140,000 at December 31, 2009. Cash and cash equivalents increased approximately $47,000 due to approximately $1,263,000 of cash provided by operating activities, partially offset by approximately $652,000 and $564,000 of cash used in investing and financing activities, respectively. Cash used in investing activities consisted of property improvements and replacements, partially offset by insurance proceeds received. Cash used in financing activities consisted of principal payments made on the mortgage notes payable and repayment of advances from AIMCO Properties, L.P., partially offset by advances from AIMCO Properties, L.P.

Pursuant to the Partnership Agreement, AIMCO Properties, L.P., an affiliate of the Managing General Partner, advanced the Partnership approximately $655,000 and $566,000 during the years ended December 31, 2010 and 2009, respectively, to fund operations at the Partnership’s investment property. AIMCO Properties, L.P. charges interest on advances under the terms permitted by the Partnership Agreement. The advances bear interest at the prime rate plus 2% (5.25% at December 31, 2010) per annum. Interest expense was approximately $31,000 and $10,000 for the years ended December 31, 2010 and 2009, respectively. During the years ended December 31, 2010 and 2009, the Partnership repaid approximately $641,000 and $71,000, respectively, of advances and accrued interest. At December 31, 2010 and 2009, the total advances and accrued interest due to AIMCO Properties, L.P. was approximately $550,000 and $505,000, respectively, and are included in due to affiliates. The Partnership may receive additional advances of funds from AIMCO Properties, L.P. although AIMCO Properties, L.P. is not obligated to provide such advances. For more information on AIMCO Properties, L.P., including copies of its audited balance sheets, please see its reports filed with the Securities and Exchange Commission. Subsequent to December 31, 2010, the Partnership paid $250,000 of principal and accrued interest.

The sufficiency of existing liquid assets to meet future liquidity and capital expenditure requirements is directly related to the level of capital expenditures required at the property to adequately maintain the physical assets and other operating needs of the Partnership and to comply with Federal, state, and local legal and regulatory requirements. The Managing General Partner monitors developments in the area of legal and regulatory compliance. The Partnership regularly evaluates the capital improvement needs of the property. While thePartnership has no material commitments for property improvements and replacements, certain routine capital expenditures are anticipated during 2011. Such capital expenditures will depend on the physical condition of the property as well as anticipated cash flow generated by the property. Capital expenditures will be incurred only if cash is available from operations, Partnership reserves or advances from AIMCO Properties, L.P., although AIMCO Properties, L.P. does not have an obligation to fund such advances. To the extent that capital improvements are completed, the Partnership’s distributable cash flow, if any, may be adversely affected at least in the short term.

The Partnership's assets are thought to be generally sufficient for any near-term needs (exclusive of capital improvements and repayment of amounts due to affiliates) of the Partnership. The mortgage indebtedness encumbering Village of Pennbrook Apartments of approximately $47,804,000 requires monthly payments of principal and interest until September 1, 2021 with balloon payments of approximately $37,859,000 due at maturity. The Managing General Partner will attempt to refinance such indebtedness and/or sell the property prior to such maturity dates. If the property cannot be refinanced or sold for a sufficient amount, the Partnership will risk losing such property through foreclosure.

The Partnership distributed the following amounts during the years ended December 31, 2010 and 2009 (in thousands, except per unit data):


	Year Ended	Per Limited	Year Ended	Per Limited
	December 31,	Partnership	December 31,	Partnership
	2010	Unit	2009	Unit

Operations	$ --	$ --	$ 575	$ 9.48

Future cash distributions will depend on the levels of cash generated from operations, the timing of the debt maturities, property sale and/or refinancings. The Partnership’s cash available for distribution is reviewed on a monthly basis. There can be no assurance, however, that the Partnership will generate sufficient funds from operations after required capital improvement expenditures and repayment of amounts due to affiliates to permit distributions to its partners in 2011 or subsequent periods.

Critical Accounting Policies and Estimates

A summary of the Partnership’s significant accounting policies is included in "Note A – Organization and Summary of Significant Accounting Policies" which is included in the financial statements in "Item 8. Financial Statements and Supplementary Data". The ManagingGeneral Partner believes that the consistent application of these policies enables the Partnership to provide readers of the financial statements with useful and reliable information about the Partnership’s operating results and financial condition. The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires the Partnership to make estimates and assumptions. These estimates and assumptions affect the reported amounts of assets and liabilities at the date of the financial statements as well as reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. Judgments and assessments of uncertainties are required in applying the Partnership’s accounting policies in many areas. The Partnership believes that of its significant accounting policies, the following may involve a higher degree of judgment and complexity.

Impairment of Long-Lived Asset

Investment property is recorded at cost, less accumulated depreciation, unless the carrying amount of the asset is not recoverable. If events or circumstances indicate that the carrying amount of the property may not be recoverable, the Partnership will make an assessment of its recoverability by comparing the carrying amount to the Partnership’s estimate of the undiscounted future cash flows, excluding interest charges, of the property. If the carrying amount exceeds the estimated aggregate undiscounted future cash flows, the Partnership would recognize an impairment loss to the extent the carrying amount exceeds the estimated fair value of the property.

Real property investment is subject to varying degrees of risk. Several factors may adversely affect the economic performance and value of the Partnership’s investment property. These factors include, but are not limited to, general economic climate; competition from other apartment communities and other housing options; local conditions, such as loss of jobs or an increase in the supply of apartments that might adversely affect apartment occupancy or rental rates; changes in governmental regulations and the related cost of compliance; increases in operating costs (including real estate taxes) due to inflation and other factors, which may not be offset by increased rents; changes in tax laws and housing laws, including the enactment of rent control laws or other laws regulating multi-family housing; andchanges in interest rates and the availability of financing. Any adverse changes in these and other factors could cause an impairment of the Partnership’s asset.

Revenue Recognition

The Partnership generally leases apartment units for twelve-month terms or less. The Partnership will offer rental concessions during particularly slow months or in response to heavy competition from other similar complexes in the area. Rental income attributable to leases, net of any concessions, is recognized on a straight-line basis over the term of the lease. The Partnership evaluates all accounts receivable from residents and establishes an allowance, after the application of security deposits, for accounts greater than 30 days past due on current tenants and all receivables due from former tenants.

Item 8. Financial Statements and Supplementary Data

NATIONAL PROPERTY INVESTORS 4

LIST OF FINANCIAL STATEMENTS

Report of Independent Registered Public Accounting Firm

Balance Sheets - December 31, 2010 and 2009

Statements of Operations - Years ended December 31, 2010 and 2009

Statements of Changes in Partners' Deficit - Years ended December 31, 2010 and 2009

Statements of Cash Flows - Years ended December 31, 2010 and 2009

Notes to Financial Statements

Report of Independent Registered Public Accounting Firm

The Partners

National Property Investors 4

We have audited the accompanying balance sheets of National Property Investors 4 as of December 31, 2010 and 2009, and the related statements of operations, changes in partners' deficit, and cash flows for each of the two years in the period ended December 31, 2010. These financial statements are the responsibility of the Partnership's management. Our responsibility is to express an opinion on these financial statements based on our audits.

We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. We were not engaged to perform an audit of the Partnership’s internal control over financial reporting. Our audits included consideration of internal control over financial reporting as a basis for designing audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of the Partnership’s internal control over financial reporting. Accordingly, we express no such opinion. An audit also includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the financial statements referred to above present fairly, in all material respects, the financial position of National Property Investors 4 at December 31, 2010 and 2009, and the results of its operations and its cash flows for each of the two years in the period ended December 31, 2010, in conformity with U.S. generally accepted accounting principles.

/s/ERNST & YOUNG LLP

Greenville, South Carolina

March 25, 2011

NATIONAL PROPERTY INVESTORS 4

BALANCE SHEETS

(in thousands, except unit data)

	December 31,
	2010	2009
Assets
Cash and cash equivalents	$ 187	$ 140
Receivables and deposits	188	145
Other assets	1,218	1,251
Investment property (Notes C, D and F):
Land	1,980	1,980
Buildings and related personal property	40,309	39,714
	42,289	41,694
Less accumulated depreciation	(33,705)	(32,070)
	8,584	9,624
	$ 10,177	$ 11,160

Liabilities and Partners' Deficit
Liabilities
Accounts payable	$ 190	$ 346
Tenant security deposit liabilities	437	421
Other liabilities	532	555
Due to affiliates (Note B)	585	549
Mortgage notes payable (Note C)	47,804	48,419
	49,548	50,290

Partners' Deficit
General partner	(538)	(536)
Limited partners	(38,833)	(38,594)
	(39,371)	(39,130)
	$ 10,177	$ 11,160

See Accompanying Notes to Financial Statements

NATIONAL PROPERTY INVESTORS 4

STATEMENTS OF OPERATIONS

(in thousands, except per unit data)

	Years Ended December 31,
	2010	2009
Revenues:
Rental income	$ 7,885	$ 7,660
Other income	1,158	1,324
Total revenues	9,043	8,984

Expenses:
Operating	3,420	3,328
General and administrative	135	179
Depreciation	1,657	1,644
Interest	3,354	3,380
Property taxes	764	752
Total expenses	9,330	9,283

Casualty gain (Note F)	46	15

Net loss (Note E)	$ (241)	$ (284)

Net loss allocated to general partner (1%)	$ (2)	$ (3)
Net loss allocated to limited partners (99%)	(239)	(281)

	$ (241)	$ (284)

Net loss per limited partnership unit	$ (3.98)	$ (4.68)

Distributions per limited partnership unit	$ --	$ 9.48

See Accompanying Notes to Financial Statements

NATIONAL PROPERTY INVESTORS 4

STATEMENTS OF CHANGES IN PARTNERS' DEFICIT

(in thousands, except unit data)

	Limited
	Partnership	General	Limited
	Units	Partner	Partners	Total

Original capital contributions	60,005	$ 1	$ 30,003	$ 30,004

Partners' deficit at
December 31, 2008	60,005	$ (527)	$(37,744)	$(38,271)

Distributions to partners	--	(6)	(569)	(575)

Net loss for the year ended
December 31, 2009	--	(3)	(281)	(284)

Partners' deficit at
December 31, 2009	60,005	(536)	(38,594)	(39,130)

Net loss for the year ended
December 31, 2010	--	(2)	(239)	(241)

Partners’ deficit at
December 31, 2010	60,005	$ (538)	$(38,833)	$(39,371)

See Accompanying Notes to Financial Statements

NATIONAL PROPERTY INVESTORS 4

STATEMENTS OF CASH FLOWS

(in thousands)

	Years Ended
	December 31,
	2010	2009
Cash flows from operating activities:
Net loss	$ (241)	$ (284)
Adjustments to reconcile net loss to net cash provided
by operating activities:
Depreciation	1,657	1,644
Amortization of loan costs	63	63
Casualty gain	(46)	(15)
Change in accounts:
Receivables and deposits	(43)	19
Other assets	(30)	(81)
Accounts payable	(75)	182
Tenant security deposit liabilities	16	(119)
Due to affiliates	(15)	53
Other liabilities	(23)	168
Net cash provided by operating activities	1,263	1,630
Cash flows from investing activities:
Insurance proceeds received	46	15
Property improvements and replacements	(698)	(1,142)
Net cash used in investing activities	(652)	(1,127)
Cash flows from financing activities:
Payments on mortgage notes payable	(615)	(465)
Distributions to partners	--	(575)
Advances from affiliate	655	566
Payments on advances from affiliate	(604)	(70)
Net cash used in financing activities	(564)	(544)

Net increase (decrease) in cash and cash equivalents	47	(41)
Cash and cash equivalents at beginning of year	140	181
Cash and cash equivalents at end of year	$ 187	$ 140

Supplemental disclosure of cash flow information:
Cash paid for interest	$ 3,296	$ 3,107

Supplemental disclosure of non-cash activity:
Property improvements and replacements included in
accounts payable	$ 18	$ 99

Included in property improvements and replacements for the year ended December 31, 2009 are approximately $13,000 of property improvements and replacements which were included in accounts payable at December 31, 2008.

See Accompanying Notes to Financial Statements

NATIONAL PROPERTY INVESTORS 4

NOTES TO FINANCIAL STATEMENTS

December 31, 2010

Note A - Organization and Summary of Significant Accounting Policies

Organization

National Property Investors 4, a California Limited Partnership (the "Partnership" or "Registrant"), was formed on July 1, 1980 to acquire, hold for investment, and ultimately sell income producing real estate property. Capital contributions of $30,002,500 ($500 per unit) were made by the limited partners. In addition, the general partner contributed $1,000. The Partnership owns one apartment complex located in Falls Township, Pennsylvania. The managing general partner is NPI Equity Investments, Inc. ("NPI Equity" or the "Managing General Partner"). The Managing General Partner is a wholly-owned subsidiary of Apartment Investment and Management Company ("AIMCO"), a publicly traded real estate investment trust. The Partnership Agreement provides that the Partnership is to terminate on December 31, 2022, unless terminated prior to such date.

Subsequent Events

The Partnership’s management evaluated subsequent events through the time this Annual Report on Form 10-K was filed.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.

Investment Property

Investment property consists of one apartment complex and is stated at cost, less accumulated depreciation, unless the carrying amount of the asset is not recoverable. The Partnership capitalizes costs incurred in connection with 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. The Partnership capitalizes interest, property taxes and insurance during periods in which redevelopment and construction projects are in progress. The Partnership did not capitalize any costs related to interest, property taxes or insurance during the years ended December 31, 2010 and 2009. Capitalized costs are depreciated over the estimated useful life of the asset. The Partnership charges to expense as incurred costs that do not relate to capital additions activities, including ordinary repairs, maintenance and resident turnover costs.

If events or circumstances indicate that the carrying amount of the property may not be recoverable, the Partnership will make an assessment of its recoverability by comparing the carrying amount to the Partnership’s estimate of the undiscounted future cash flows, excluding interest charges, of the property. If the carrying amount exceeds the estimated aggregate undiscounted future cash flows, the Partnership would recognize an impairment loss to the extent the carrying amountexceeds the estimated fair value of the property. No adjustments for impairment of value were necessary for the years ended December 31, 2010 and 2009.

Depreciation

Depreciation is provided by the straight-line method over the estimated lives of the apartment property and related personal property. For Federal income tax purposes, the modified accelerated cost recovery method is used for depreciation of (1) real property additions over 27.5 years and (2) personal property additions over 5 years.

Cash and Cash Equivalents

Cash and cash equivalents include cash on hand and in banks. At certain times, the amount of cash deposited at a bank may exceed the limit on insured deposits. Cash balances include approximately $65,000 and zero at December 31, 2010 and 2009, respectively, that are maintained by an affiliated management company on behalf of affiliated entities in cash concentration accounts.

Deferred Costs

Loan costs of approximately $1,149,000, less accumulated amortization of approximately $468,000 and $405,000, are included in other assets at December 31, 2010 and 2009, respectively. The loan costs are amortized over the terms of the related loan agreements. Amortization expense for both years ended December 31, 2010 and 2009 was approximately $63,000 and is included in interest expense. Amortization expense is expected to be approximately $63,000 for each of the years 2011 through 2015.

Leasing commissions and other direct costs incurred in connection with successful leasing efforts are deferred and amortized over the terms of the related leases. Amortization of these costs is included in operating expenses.

Tenant Security Deposits

The Partnership requires security deposits from lessees for the duration of the lease. Deposits are refunded when the tenant vacates, provided the tenant has not damaged the space and is current on rental payments.

Fair Value of Financial Instruments

Financial Accounting Standards Board Accounting Standards Codification (“ASC”) Topic 825, “Financial Instruments”, requires disclosure of fair value information about financial instruments, whether or not recognized in the balance sheet, for which it is practicable to estimate fair value. Fair value is defined as the amount at which the instruments could be exchanged in a current transaction between willing parties, other than in a forced or liquidation sale. The Partnership believes that the carrying amount of its financial instruments (except for mortgage notes payable) approximates their fair value due to the short-term maturity of these instruments. The Partnership estimates the fair value of its mortgage notes payable by discounting future cash flows using a discount rate commensurate with that currently believed to be available to the Partnership for similar term, mortgage notes payable. At December 31, 2010, the fair value of the Partnership's mortgage notes payable at the Partnership's incremental borrowing rate was approximately $53,237,000.

Leases

The Partnership generally leases apartment units for twelve-month terms or less. The Partnership will offer rental concessions during particularly slow months or inresponse to heavy competition from other similar complexes in the area. Rental income attributable to leases, net of any concessions, is recognized on a straight-line basis over the term of the lease. The Partnership evaluates all accounts receivable from residents and establishes an allowance, after the application of security deposits, for accounts greater than 30 days past due on current tenants and all receivables due from former tenants.

Allocation of Profits, Gains, and Losses

Profits, gains, and losses of the Partnership are allocated between the general partner and the limited partners in accordance with the provisions of the Partnership Agreement.

Advertising Costs

The Partnership expenses the cost of advertising as incurred. Advertising costs of approximately $76,000 and $41,000 during the years ended December 31, 2010 and 2009, respectively, were charged to expense as incurred and are included in operating expenses.

Segment Reporting

ASC Topic 280-10, “Segment Reporting”, established standards for the way public business enterprises report information about operating segments in annual financial statements and requires that those enterprises report selected information about operating segments in interim financial reports. ASC Topic 280-10 also established standards for related disclosures about products and services, geographic areas, and major customers. As defined in ASC Topic 280-10, the Partnership has only one reportable segment.

Note B - Transactions with Affiliated Parties

The Partnership has no employees and depends on the Managing General Partner and its affiliates for the management and administration of all Partnership activities. The Partnership Agreement provides for payments to affiliates for services and for reimbursement of certain expenses incurred by affiliates on behalf of the Partnership.

Affiliates of the Managing General Partner receive 5% of gross receipts from the Partnership's property as compensation for providing property management services. The Partnership paid to such affiliates approximately $445,000 for both of the years ended December 31, 2010 and 2009, which are included in operating expenses.

Affiliates of the Managing General Partner charged the Partnership for reimbursement of accountable administrative expenses amounting to approximately $126,000 and $183,000 for the years ended December 31, 2010 and 2009, respectively, which are included in general and administrative expenses and investment property. The portion of these reimbursements included in investment property for the years ended December 31, 2010 and 2009 are amounts related to construction management services provided by an affiliate of the Managing General Partner of approximately $43,000 and $102,000, respectively. At December 31, 2010 and 2009, approximately $35,000 and $44,000 was owed for accountable administrative expenses, respectively, and is included in due to affiliates.

For services relating to the administration of the Partnership and operation of the Partnership's property, the Managing General Partner is entitled to receive payment for non-accountable expenses up to a maximum of $100,000 per year based upon the number of Partnership units sold, subject to certain limitations. The Managing General Partner received approximately $19,000 for the year ended December 31, 2009which is included in general and administrative expenses. No such reimbursements were made during the year ended December 31, 2010.

In addition to the amounts discussed above, as compensation for services rendered in managing the Partnership, the Managing General Partner is entitled to receive a Partnership Management Fee in conjunction with distributions of cash from operations, subject to certain limitations. During the year ended December 31, 2009, approximately $31,000 was paid in conjunction with the distributions from operations and is included in general and administrative expenses. There were no such fees paid during the year ended December 31, 2010, as there were no distributions from operations.

Pursuant to the Partnership Agreement, AIMCO Properties, L.P., an affiliate of the Managing General Partner, advanced the Partnership approximately $655,000 and $566,000 during the years ended December 31, 2010 and 2009, respectively, to fund operations at the Partnership’s investment property. AIMCO Properties, L.P. charges interest on advances under the terms permitted by the Partnership Agreement. The advances bear interest at the prime rate plus 2% (5.25% at December 31, 2010) per annum. Interest expense was approximately $31,000 and $10,000 for the years ended December 31, 2010 and 2009, respectively. During the years ended December 31, 2010 and 2009, the Partnership repaid approximately $641,000 and $71,000, respectively, of advances and accrued interest. At December 31, 2010 and 2009, the total advances and accrued interest due to AIMCO Properties, L.P. was approximately $550,000 and $505,000, respectively, and are included in due to affiliates. The Partnership may receive additional advances of funds from AIMCO Properties, L.P. although AIMCO Properties, L.P. is not obligated to provide such advances. Subsequent to December 31, 2010, the Partnership paid $250,000 of principal and accrued interest.

The Partnership insures its property up to certain limits through coverage provided by AIMCO which is generally self-insured for a portion of losses and liabilities related to workers compensation, property casualty, general liability and vehicle liability. The Partnership insures its property above the AIMCO limits through insurance policies obtained by AIMCO from insurers unaffiliated with the Managing General Partner. During the years ended December 31, 2010 and 2009, the Partnership was charged by AIMCO and its affiliates approximately $149,000 and $111,000, respectively, for insurance coverage and fees associated with policy claims administration.

In addition to its indirect ownership of the general partner interest in the Partnership, AIMCO and its affiliates owned 47,850 Units in the Partnership representing 79.74% of the outstanding Units at December 31, 2010. A number of these Units were acquired pursuant to tender offers made by AIMCO or its affiliates. It is possible that AIMCO or its affiliates will acquire additional Units in exchange for cash or a combination of cash and units in AIMCO Properties, L.P., the operating partnership of AIMCO, either through private purchases or tender offers. Pursuant to the Partnership Agreement, unitholders holding a majority of the Units are entitled to take action with respect to a variety of matters that include, but are not limited to, voting on certain amendments to the Partnership Agreement and voting to remove the Managing General Partner. As a result of its ownership of 79.74% of the outstanding Units, AIMCO is in a position to influence all such voting decisions with respect to the Partnership. With respect to 26,466 Units, AIMCO IPLP, L.P., an affiliate of AIMCO, is required to vote such Units: (i) against any increase in compensation payable to the Managing General Partner or to affiliates; and (ii) on all other matters submitted by it or its affiliates, in proportion to the votes cast by non-tendering unitholders. Except for the foregoing, no other limitations are imposed on AIMCO's or AIMCO IPLP, L.P.'s ability to influence voting decisions with respect to the Partnership. Although the Managing General Partner owes fiduciary duties to the limited partners of the Partnership, the Managing General Partner also owes fiduciary duties toAIMCO as its sole stockholder. As a result, the duties of the Managing General Partner, as managing general partner, to the Partnership and its limited partners may come into conflict with the duties of the Managing General Partner to AIMCO as its sole stockholder.

Note C - Mortgage Notes Payable

The terms of the mortgage notes payable are as follows:


	Principal				Monthly			Principal
	Balance At		Stated		Payment			Balance
	December 31,		Interest		Including	Period	Maturity	Due At
Property	2010	2009	Rate		Interest	Amortized	Date	Maturity
	(in thousands)			(in thousands)				(in thousands)
Village of
Pennbrook
Apartments
1^st mortgage	$25,061	$25,399	7.06%		$ 177	30 yrs	09/01/21	$19,515
2^nd mortgage	13,030	13,187	6.32% (1)		82	30 yrs	09/01/21	10,561
3^rd mortgage	9,713	9,833	6.62%		64	30 yrs	09/01/21	7,783
	$47,804	$48,419			$ 323			$37,859

(1) Monthly payment of interest only until August 1, 2009, when monthly payments of principal and interest of approximately $82,000 began.

The mortgage notes payable are fixed rate mortgages that are non-recourse and are secured by pledge of the Partnership’s rental property and by pledge of revenues from the rental property. The mortgage notes payable include prepayment penalties if repaid prior to maturity. Further, the property may not be sold subject to existing indebtedness.

Scheduled principal payments subsequent to December 31, 2010 are as follows (in thousands):

2011	$ 658
2012	704
2013	753
2014	806
2015	862
Thereafter	44,021
	$47,804

Note D – Investment Property and Accumulated Depreciation

		Initial Cost
		To Partnership
		(in thousands)

			Buildings	Net Cost
			and Related	Capitalized
			Personal	Subsequent to
Description	Encumbrances	Land	Property	Acquisition
	(in thousands)			(in thousands)

Villageof PennbrookApartments	$47,804	$ 1,972	$18,245	$22,072

	Gross Amount At Which Carried
	At December 31, 2010
	(in thousands)

		Buildings
		And Related
		Personal		Accumulated	Date	Depreciable
Description	Land	Property	Total	Depreciation	Acquired	Life
				(in thousands)
Villageof Pennbrook
Apartments	$ 1,980	$40,309	$42,289	$33,705	12/81	5-30 yrs

Reconciliation of "Investment Property and Accumulated Depreciation":

	Years Ended
	December 31,
	2010	2009
	(in thousands)
Investment Property
Balance at beginning of year	$41,694	$40,473
Property improvements	617	1,228
Disposals of property	(22)	(7)
Balance at end of year	$42,289	$41,694

Accumulated Depreciation
Balance at beginning of year	$32,070	$30,433
Additions charged to expense	1,657	1,644
Disposals of property	(22)	(7)
Balance at end of year	$33,705	$32,070

The aggregate cost of the real estate for Federal income tax purposes at December 31, 2010 and 2009 is approximately $19,805,000 and $18,898,000, respectively. The accumulated depreciation taken for Federal income tax purposes at December 31, 2010 and 2009 is approximately $10,495,000 and $9,345,000, respectively.

Note E - Income Taxes

The Partnership is classified as a partnership for Federal income tax purposes. Accordingly, no provision for income taxes is made in the financial statements of the Partnership. Taxable income or loss of the Partnership is reported in the income tax returns of its partners.

The following is a reconciliation of reported net loss and Federal taxable income (in thousands, except per unit data):

	Years Ended December 31,
	2010	2009
Net loss as reported	$ (241)	$ (284)
(Deduct) add:
Depreciation differences	507	396
Prepaid rent	(12)	(10)
Other	(108)	(90)

Federal taxable income	$ 146	$ 12

Federal taxable income per limited
partnership unit	$ 2.41	$ 0.20

The following is a reconciliation between the Partnership's reported amounts and Federal tax basis of net liabilities (in thousands):

	2010	2009
Net liabilities as reported	$(39,371)	$(39,130)
Land and buildings	(22,484)	(22,796)
Accumulated depreciation	23,210	22,725
Syndication and distribution costs	3,375	3,375
Other	183	593

Net liabilities - Federal tax basis	$(35,087)	$(35,233)

Note F – Casualty Events

Note G - Contingencies

As previously disclosed, AIMCO Properties, L.P. and NHP Management Company, both affiliates of the Managing General Partner, were defendants in a lawsuit, filed as a collective action in August 2003 in the United States District Court for the District of Columbia, alleging that they willfully violated the Fair Labor Standards Act (“FLSA”) by failing to pay maintenance workers overtime for time worked in excess of 40 hours per week (“overtime claims”). The plaintiffs also contended that AIMCO Properties, L.P. and NHP Management Company (“the Defendants”) failed to compensate maintenance workers for time that they were required to be "on-call" (“on-call claims”). In March 2007, the court in the District of Columbia decertified the collective action. In July 2007, plaintiffs’ counsel filed individual cases in Federal court in 22 jurisdictions. In the second quarter of 2008, AIMCO Properties, L.P. settled the overtime cases involving 652 plaintiffs and established a framework for resolving the 88 remaining “on-call” claims and the attorneys’ fees claimed by plaintiffs’ counsel. As a result, the lawsuits asserted in the 22 Federal courts were dismissed. During the fourth quarter of 2008, thesettlement amounts for alleged unpaid overtime to employees were paid by those partnerships where the respective employees had worked. The Partnership was not required to pay any settlement amounts. During January 2011, the parties reached an agreement to settle the remaining “on-call claims” and the plaintiffs’ attorneys’ fees. The Partnership will not be required to pay any settlement amounts or plaintiffs’ attorneys’ fees as a result of this agreement. These settlements resolve the case in its entirety.

The Partnership is unaware of any other pending or outstanding litigation matters involving it or its investment property that are not of a routine nature arising in the ordinary course of business.

Environmental

Various Federal, state and local laws subject property owners or operators to liability for management, and the costs of removal or remediation, of certain potentially hazardous materials present on a property, including lead-based paint, asbestos, polychlorinated biphenyls, petroleum-based fuels, and other miscellaneous materials. Such laws often impose liability without regard to whether the owner or operator knew of, or was responsible for, the release or presence of such materials. The presence of, or the failure to manage or remedy properly, these materials may adversely affect occupancy at affected apartment communities and the ability to sell or finance affected properties. In addition to the costs associated with investigation and remediation actions brought by government agencies, and potential fines or penalties imposed by such agencies in connection therewith, improper management of these materials on a property could result in claims by private plaintiffs for personal injury, disease, disability or other infirmities. Various laws also impose liability for the cost of removal, remediation or disposal of these materials through a licensed disposal or treatment facility. Anyone who arranges for the disposal or treatment of these materials is potentially liable under such laws. These laws often impose liability whether or not the person arranging for the disposal ever owned or operated the disposal facility. In connection with the ownership, operation and management of its property, the Partnership could potentially be responsible for environmental liabilities or costs associated with its property.

ITEM 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

None.

Item 9A. Controls and Procedures

(a) Disclosure Controls and Procedures

The Partnership’s management, with the participation of the principal executive officer and principal financial officer of the Managing General Partner, who are the equivalent of the Partnership’s principal executive officer and principal financial officer, respectively, has evaluated the effectiveness of the Partnership’s disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”)) as of the end of the period covered by this report. Based on such evaluation, the principal executive officer and principal financial officer of the Managing General Partner, who are the equivalent of the Partnership’s principal executive officer and principal financial officer, respectively, have concluded that, as of the end of such period, the Partnership’s disclosure controls and procedures are effective.

Management’s Report on Internal Control Over Financial Reporting

The Partnership’s management is responsible for establishing and maintaining adequate internal control over financial reporting. Internal control over financial reporting is defined in Rule 13a-15(f) and 15d-15(f) under the Exchange Act as a process designed by, or under the supervision of, the principal executive and principal financial officers of the Managing General Partner, who are the equivalent of the Partnership’s principal executive officer and principal financial officer, respectively, and effected by the Partnership’s management and other personnel to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles and includes those policies and procedures that:

· pertain to the maintenance of records that in reasonable detail accurately and fairly reflect the transactions and dispositions of assets;

· provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures are being made only in accordance with authorizations of the Partnership’s management; and

· provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Projections of any evaluation of effectiveness to future periods are subject to the risks that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

The Partnership’s management assessed the effectiveness of the Partnership’s internal control over financial reporting as of December 31, 2010. In making this assessment, the Partnership’s management used the criteria set forth by theCommittee of Sponsoring Organizations of the Treadway Commission (COSO) inInternal Control-Integrated Framework.

Based on their assessment, the Partnership’s management concluded that, as of December 31, 2010, the Partnership’s internal control over financial reporting is effective.

This annual report does not include an attestation report of the Partnership’s registered public accounting firm regarding internal control over financial reporting. Management’s report was not subject to attestation by the Partnership’s registered public accounting firm pursuant to rules of the Securities and Exchange Commission that permit the Partnership to provide only management’s report in this annual report.

(b) Changes in Internal Control Over Financial Reporting.

There has been no change in the Partnership’s internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) during the fourth quarter of 2010 that has materially affected, or is reasonably likely to materially affect, the Partnership’s internal control over financial reporting.

Item 9B. Other Information

None.

PART III

Item 10. Directors, Executive Officers and Corporate Governance

The Partnership has no directors or officers. The Managing General Partner is NPI Equity Investments, Inc. The names and ages of, as well as the position and offices held by, the present director and officers of the Managing General Partner are set forth below. There are no family relationships between or among any directors or officers.

Name	Age	Position

Steven D. Cordes	39	Director and Senior Vice President
John Bezzant	48	Director and Executive Vice President
Ernest M. Freedman	40	Executive Vice President and Chief Financial Officer
Lisa R. Cohn	42	Executive Vice President, General Counsel and Secretary
Paul Beldin	37	Senior Vice President and Chief Accounting Officer
Stephen B. Waters	49	Senior Director of Partnership Accounting

Steven D. Cordes was appointed as a Director of the Managing General Partner effective March 2, 2009. Mr. Cordes has been a Senior Vice President of the Managing General Partner and AIMCO since May 2007. Mr. Cordes joined AIMCO in 2001 as a Vice President of Capital Markets with responsibility for AIMCO’s joint ventures and equity capital markets activity. Prior to joining AIMCO, Mr. Cordes was a manager in the financial consulting practice of PricewaterhouseCoopers. Effective March 2009, Mr. Cordes was appointed to serve as the equivalent of the chief executive officer of the Partnership. Mr. Cordes brings particular expertise to the Board in the areas of asset management as well as finance and accounting.

John Bezzant was appointed as a Director of the Managing General Partner effective December 16, 2009. Mr. Bezzant was appointed Executive Vice President of the Managing General Partner and AIMCO in January 2011 and prior to that time was a Senior Vice President of the Managing General Partner and AIMCO since joining AIMCO in June 2006. Prior to joining AIMCO, Mr. Bezzant spent over 20 years with Prologis, Inc. and Catellus Development Corporation in a variety of executive positions, including those with responsibility for transactions, fund management, asset management, leasing and operations. Mr. Bezzant brings particular expertise to the Board in the areas of real estate finance, property operations, sales and development.

Ernest M. Freedman was appointed Executive Vice President and Chief Financial Officer of the Managing General Partner and AIMCO in November 2009. Mr. Freedman joined AIMCO in 2007 as Senior Vice President of Financial Planning and Analysis and has served as Senior Vice President of Finance since February 2009, responsible for financial planning, tax, accounting and related areas. Prior to joining AIMCO, from 2004 to 2007, Mr. Freedman served as chief financial officer of HEI Hotels and Resorts.

Lisa R. Cohn was appointed Executive Vice President, General Counsel and Secretary of the Managing General Partner and AIMCO in December 2007. From January 2004 to December 2007, Ms. Cohn served as Senior Vice President and Assistant General Counsel of AIMCO. Ms. Cohn joined AIMCO in July 2002 as Vice President and Assistant General Counsel. Prior to joining AIMCO, Ms. Cohn was in private practice with the law firm of Hogan and Hartson LLP.

Paul Beldin joined AIMCO in May 2008 and has served as Senior Vice President and Chief Accounting Officer of AIMCO and the Managing General Partner since that time. Prior to joining AIMCO, Mr. Beldin served as controller and then as chief financial officer of America First Apartment Investors, Inc., a publicly traded multifamily real estate investment trust, from May 2005 to September 2007 when the company was acquired by Sentinel Real Estate Corporation. Prior to joining America First Apartment Investors, Inc., Mr. Beldin was a senior manager at Deloitte and Touche LLP, where he was employed from August 1996 to May 2005, including two years as an audit manager in SEC services at Deloitte’s national office.

Stephen B. Waters was appointed Senior Director of Partnership Accounting of AIMCO and the Managing General Partner in June 2009. Mr. Waters has responsibility for partnership accounting with AIMCO and serves as the principal financial officer of the Managing General Partner. Mr. Waters joined AIMCO as a Director of Real Estate Accounting in September 1999 and was appointed Vice President of the Managing General Partner and AIMCO in April 2004. Prior to joining AIMCO, Mr. Waters was a senior manager at Ernst & Young LLP.

The Registrant is not aware of the involvement in any legal proceedings with respect to the directors and executive officers listed in this Item 10.

One or more of the above persons are also directors and/or officers of a general partner (or general partner of a general partner) of limited partnerships which either have a class of securities registered pursuant to Section 12(g) of the Securities Exchange Act of 1934, or are subject to the reporting requirements of Section 15(d) of such Act: Further, one or more of the above persons are also officers of Apartment Investment and Management Company and the general partner of AIMCO Properties, L.P., entities that have a class of securities registered pursuant to Section 12(g) of the Securities Exchange Act of 1934, or are subject to the reporting requirements of Section 15 (d) of such Act.

The board of directors of the Managing General Partner does not have a separate audit committee. As such, the board of directors of the Managing General Partner fulfills the functions of an audit committee. The board of directors has determined that Steven D. Cordes meets the requirement of an "audit committee financial expert".

The directors and officers of the Managing General Partner with authority over the Partnership are all employees of subsidiaries of AIMCO. AIMCO has adopted a code of ethics that applies to such directors and officers that is posted on AIMCO's website (www.AIMCO.com). AIMCO's website is not incorporated by reference to this filing.

Item 11. Executive Compensation

Neither the directors nor the officers of the Managing General Partner received any remuneration from the Registrant during the years ended December 31, 2010 and 2009.

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Security Holder Matters

Except as noted below, as of December 31, 2010, no person or entity was known to own of record or beneficially more than five percent of the limited partnership units (“the Units”) of the Partnership.

	Number of	Percent
	Units	of Total
AIMCO IPLP, L.P.	32,525	54.20%
(an affiliate of AIMCO)
IPLP Acquisition I, LLC	4,452	7.42%
(an affiliate of AIMCO)
AIMCO Properties, L.P.	10,873	18.12%
(an affiliate of AIMCO)

AIMCO IPLP, L.P. and IPLP Acquisition I, LLC are indirectly ultimately owned by AIMCO. Their business address is 55 Beattie Place, Greenville, SC 29601.

AIMCO Properties, L.P. is indirectly ultimately controlled by AIMCO. Its business address is 4582 S. Ulster St. Parkway, Suite 1100, Denver, CO 80237.

No director or officer of the Managing General Partner owns any Units.

Item 13. Certain Relationships and Related Transactions, and Director Independence

Affiliates of the Managing General Partner charged the Partnership for reimbursement of accountable administrative expenses amounting to approximately $126,000 and $183,000 for the years ended December 31, 2010 and 2009, respectively, which are included in general and administrative expenses and investment property on the financial statements included in “Item 8. Financial Statements and Supplementary Data”. The portion of these reimbursements included in investment property for the years ended December 31, 2010 and 2009 are amounts related to construction management services provided by an affiliate of the Managing General Partner of approximately $43,000 and $102,000, respectively. At December 31, 2010 and 2009, approximately $35,000 and $44,000 was owed for accountable administrative expenses, respectively, and are included in due to affiliates on the balance sheets included in “Item 8. Financial Statements and Supplementary Data”.

For services relating to the administration of the Partnership and operation of the Partnership's property, the Managing General Partner is entitled to receive payment for non-accountable expenses up to a maximum of $100,000 per year based upon the number of Partnership units sold, subject to certain limitations. The Managing General Partner received approximately $19,000 for the year ended December 31, 2009which is included in general and administrative expenses on the statements of operations included in “Item 8. Financial Statements and Supplementary Data”. No such reimbursements were made during the year ended December 31, 2010.

In addition to the amounts discussed above, as compensation for services rendered in managing the Partnership, the Managing General Partner is entitled to receive a Partnership Management Fee in conjunction with distributions of cash from operations, subject to certain limitations. During the year ended December 31, 2009, approximately $31,000 was paid in conjunction with the distributions from operations and is included in general and administrative expenses on the statements of operations included in “Item 8. Financial Statements and Supplementary Data”. There were no such fees paid during the year ended December 31, 2010, as there were no distributions from operations.

Pursuant to the Partnership Agreement, AIMCO Properties, L.P., an affiliate of the Managing General Partner, advanced the Partnership approximately $655,000 and $566,000 during the years ended December 31, 2010 and 2009, respectively, to fund operations at the Partnership’s investment property. AIMCO Properties, L.P. charges interest on advances under the terms permitted by the Partnership Agreement. The advances bear interest at the prime rate plus 2% (5.25% at December 31, 2010) per annum. Interest expense was approximately $31,000 and $10,000 for the years ended December 31, 2010 and 2009, respectively. During the years ended December 31, 2010 and 2009, the Partnership repaid approximately $641,000 and $71,000, respectively, of advances and accrued interest. At December 31, 2010 and 2009, the total advances and accrued interest due to AIMCO Properties, L.P. was approximately $550,000 and $505,000, respectively, and are included in due to affiliates on the balance sheets included in “Item 8. Financial Statements and Supplementary Data”. The Partnership may receive additional advances of funds from AIMCO Properties, L.P. although AIMCO Properties, L.P. is not obligated to provide such advances. Subsequent to December 31, 2010, the Partnership paid $250,000 of principal and accrued interest.

In addition to its indirect ownership of the general partner interest in the Partnership, AIMCO and its affiliates owned 47,850 Units in the Partnership representing 79.74% of the outstanding Units at December 31, 2010. A number of these Units were acquired pursuant to tender offers made by AIMCO or its affiliates. It is possible that AIMCO or its affiliates will acquire additional Units in exchange for cash or a combination of cash and units in AIMCO Properties, L.P., the operating partnership of AIMCO, either through private purchases or tender offers. Pursuant to the Partnership Agreement, unitholders holding a majority of the Units are entitled to take action with respect to a variety of matters that include, but are not limited to, voting on certain amendments to the Partnership Agreement and voting to remove the Managing General Partner. As a result of its ownership of 79.74% of the outstanding Units, AIMCO is in a position to influence all such voting decisions with respect to the Partnership. With respect to 26,466 Units, AIMCO IPLP, L.P., an affiliate of AIMCO, is required to vote such Units: (i) against any increase in compensation payable to the Managing General Partner or to affiliates; and (ii) on all other matters submitted by it or its affiliates, in proportion to the votes cast by non-tendering unitholders. Except for the foregoing, no other limitations are imposed on AIMCO's or AIMCOIPLP, L.P.'s ability to influence voting decisions with respect to the Partnership. Although the Managing General Partner owes fiduciary duties to the limited partners of the Partnership, the Managing General Partner also owes fiduciary duties to AIMCO as its sole stockholder. As a result, the duties of the Managing General Partner, as managing general partner, to the Partnership and its limited partners may come into conflict with the duties of the Managing General Partner to AIMCO as its sole stockholder.

Neither of the Managing General Partner’s directors is independent under the independence standards established for New York Stock Exchange listed companies as both directors are employed by the parent of the Managing General Partner.

Item 14. Principal Accounting Fees and Services

The Managing General Partner has reappointed Ernst & Young LLP as independent auditors to audit the financial statements of the Partnership for 2011. The aggregate fees billed for services rendered by Ernst & Young LLP for 2010 and 2009 are described below.

Audit Fees. Fees for audit services totaled approximately $41,000 and $38,000 for 2010 and 2009, respectively. Fees for audit services also include fees for the reviews of the Partnership’s Quarterly Reports on Form 10-K.

Tax Fees. Fees for tax services totaled approximately $6,000 for both 2010 and 2009.

PART IV

Item 15. Exhibits, Financial Statement Schedules

(a) The following financial statements of the Partnership are included in Item 8:

Balance Sheets at December 31, 2010 and 2009.

Statements of Operations for the years ended December 31, 2010 and 2009.

Statements of Changes in Partners' Deficit for the years ended December 31, 2010 and 2009.

Statements of Cash Flows for the years ended December 31, 2010 and 2009.

Notes to Financial Statements.

Schedules are omitted for the reason that they are inapplicable or equivalent information has been included elsewhere herein.

b) Exhibits:

See Exhibit index

The agreements included as exhibits to this Form 10-K contain representations and warranties by each of the parties to the applicable agreement. These representations and warranties have been made solely for the benefit of the other parties to the applicable agreement and:

should not in all instances be treated as categorical statements of fact, but rather as a way of allocating the risk to one of the parties if those statements prove to be inaccurate;

have been qualified by disclosures that were made to the other party in connection with the negotiation of the applicable agreement, which disclosures are not necessarily reflected in the agreement;

may apply standards of materiality in a way that is different from what may be viewed as material to an investor; and

were made only as of the date of the applicable agreement or such other date or dates as may be specified in the agreement and are subject to more recent developments.

Accordingly, these representations and warranties may not describe the actual state of affairs as of the date they were made or at any other time. The Partnership acknowledges that, notwithstanding the inclusion of the foregoing cautionary statements, it is responsible for considering whether additional specific disclosures of material information regarding material contractual provisions are required to make the statements in this Form 10-K not misleading. Additional information about the Partnership may be found elsewhere in this Form 10-K and the Partnership’s other public filings, which are available without charge through the SEC’s website athttp://www.sec.gov.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	NATIONAL PROPERTY INVESTORS 4

	By: NPI EQUITY INVESTMENTS, INC.
	Managing General Partner

	By: /s/Steven D. Cordes
	Steven D. Cordes
	Senior Vice President

	By: /s/Stephen B. Waters
	Stephen B. Waters
	Senior Director of Partnership Accounting

	Date: March 25, 2011

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

/s/John Bezzant	Director and Executive	Date: March 25, 2011
John Bezzant	Vice President

/s/Steven D. Cordes	Director and Senior	Date: March 25, 2011
Steven D. Cordes	Vice President

/s/Stephen B. Waters	Senior Director of Partnership	Date: March 25, 2011
Stephen B. Waters	Accounting

NATIONAL PROPERTY INVESTORS 4

EXHIBIT INDEX

Exhibit Description of Exhibit

2.1 NPI, Inc. Stock Purchase Agreement dated as of August 17, 1995, incorporated by reference to the Partnership's Current Report on Form 8-K dated August 17, 1995.

2.2 Partnership Units Purchase Agreement dated as of August 17, 1995 incorporated by reference to Current Report on Form 8-K filed by Insignia Financial Group, Inc. ("Insignia") with the Securities and Exchange Commission on September 1, 1995.

2.3 Management Purchase Agreement dated as of August 17, 1995, incorporated by reference to Current Report on Form 8-K filed by Insignia Financial Group, Inc. with the Securities and Exchange Commission on September 1, 1995.

3.4 Agreement of Limited Partnership, incorporated by reference to Exhibit A to the Prospectus of the Partnership dated September 20, 1983, as amended on June 13 1989, and as thereafter supplemented contained in the fiscal Partnership's Registration Statement on Form S-11 (Reg. No. 2-63733).

3.4a Amendment to the Limited Partnership Agreement dated December 22, 2005 initially filed with the Registrant’s Annual Report on Form 10-KSB for the fiscal year ended December 31, 2005 and incorporated herein by reference.

10.1 Agreement to Purchase Village of Pennbrook Apartments dated November 25, 1981 between the Partnership and SB Partners, incorporated by reference to the Partnership's Current Report on Form 8-K dated November 25, 1981.

10.8 Multifamily Note dated June 30, 2006 between National Property Investors 4, a California limited partnership, and Capmark Finance Inc., a California corporation, incorporated by reference to the Partnership’s Current Report on Form 8-K dated June 30, 2006.

10.9 Amended and Restated Multifamily Mortgage, Assignment of Rents and Security Agreement dated June 30, 2006 between National Property Investors 4, a California limited partnership, and the Federal Home Loan Mortgage Corporation, incorporated by reference to the Partnership’s Current Report on Form 8-K dated June 30, 2006.

10.10 Amended and Restated Multifamily Note dated June 30, 2006 between National Property Investors 4, a California limited partnership, and the Federal Home Loan Mortgage Corporation, incorporated by reference to the Partnership’s Current Report on Form 8-K dated June 30, 2006.

10.11 Amended and Restated Guaranty, dated June 30, 2006 between National Property Investors 4, a California limited partnership, and the Federal Home Loan Mortgage Corporation, incorporated by reference to the Partnership’s Current Report on Form 8-K dated June 30, 2006.

10.13 Multifamily Note dated May 30, 2008 between National Property Investors 4, a California limited partnership, and Capmark Bank in reference to Village of Pennbrook Apartments, incorporated by reference to the Partnership’s Current Report on Form 8-K dated May 30, 2008.

10.14 Multifamily Mortgage, Assignment of Rents and Security Agreement dated May 30, 2008 between National Property Investors 4, a California limited partnership and Capmark Bank in reference to Village of Pennbrook Apartments,incorporated by reference to the Partnership’s Current Report on Form 8-K dated May 30, 2008.

31.1 Certification of equivalent of Chief Executive Officer pursuant to Securities Exchange Act Rules 13a-14(a)/15d-14(a), as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

31.2 Certification of equivalent of Chief Financial Officer pursuant to Securities Exchange Act Rules 13a-14(a)/15d-14(a), as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

32.1 Certification of equivalent of Chief Executive Officer and Chief Financial Officer pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

Positive
Negative
Uncertain
Constraining
Legalese
Litigous
Readability	8th grade Avg

National Property Investors 4 Inactive 10-K2010 FY Annual report

Content analysis

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Form 10-K

NATIONAL PROPERTY INVESTORS 4

PART I

PART II

Units

Partner

Partners

NOTES TO FINANCIAL STATEMENTS

Note A - Organization and Summary of Significant Accounting Policies

PART IV