UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549



Form 10-QSB



(Mark One)

[X]

QUARTERLY REPORT UNDER SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934



For the quarterly period ended March 31, 2006





[ ]

TRANSITION REPORT UNDER SECTION 13 OR 15(d) OF THE EXCHANGE ACT





For the transition period from _________to _________



Commission file number 0-10412





NATIONAL PROPERTY INVESTORS 4

(Exact name of small business issuer 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)



(864) 239-1000

(Issuer's telephone number)





Check whether the issuer (i) filed all reports required to be filed by Section 13 or 15(d) of the Exchange Act during the past 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 is a shell company (as defined in Rule 12b-2 of the Exchange Act) Yes __ No  X_















PART I  FINANCIAL INFORMATION





ITEM 1.

FINANCIAL STATEMENTS







NATIONAL PROPERTY INVESTORS 4

BALANCE SHEET

(Unaudited)

(in thousands, except unit data)





March 31, 2006







|                                        |           |         
|--------------------------------------- | --------- | --------
|Assets                                  |           |         
|Cash and cash equivalents               |           | $    365
|Receivables and deposits                |           | 136     
|Other assets                            |           | 1,127   
|Investment property:                    |           |         
|Land                                    | $  1,980  |         
|Buildings and related personal property | 35,030    |         
|                                        | 37,010    |         
|Less accumulated depreciation           | (26,404)  | 10,606  
|                                        |           | $12,234 
|Liabilities and Partners' Deficit       |           |         
|Liabilities                             |           |         
|Accounts payable                        |           | $    596
|Tenant security deposit liabilities     |           | 431     
|Other liabilities                       |           | 416     
|Due to affiliates (Note B)              |           | 5,306   
|Mortgage note payable                   |           | 26,709  
|                                        |           |         
|Partners' Deficit                       |           |         
|General partner                         | $   (358) |         
|Limited partners (60,005 units          |           |         
|issued and outstanding)                 | (20,866)  | (21,224)
|                                        |           | $12,234 



























See Accompanying Notes to Financial Statements

















NATIONAL PROPERTY INVESTORS 4

STATEMENTS OF OPERATIONS

(Unaudited)

(in thousands, except per unit data)







|                                               |                    |        
|---------------------------------------------- | ------------------ | -------
|                                               | Three Months Ended
|                                               | March 31,         
|                                               | 2006               | 2005   
|Revenues:                                      |                    |        
|Rental income                                  | $ 1,980            | $ 1,791
|Other income                                   | 148                | 113    
|Total revenues                                 | 2,128              | 1,904  
|                                               |                    |        
|Expenses:                                      |                    |        
|Operating                                      | 915                | 760    
|General and administrative                     | 47                 | 40     
|Depreciation                                   | 358                | 149    
|Interest                                       | 603                | 504    
|Property taxes                                 | 168                | 164    
|Total expenses                                 | 2,091              | 1,617  
|                                               |                    |        
|Net income                                     | $37                | $287   
|                                               |                    |        
|Net income allocated to general partner (1%)   | $    --            | $     3
|                                               |                    |        
|Net income allocated to limited partners (99%) | 37                 | 284    
|                                               | $37                | $287   
|                                               |                    |        
|Net income per limited partnership unit        | $0.62              | $4.73  













































See Accompanying Notes to Financial Statements





















NATIONAL PROPERTY INVESTORS 4

STATEMENT OF CHANGES IN PARTNERS' DEFICIT

(Unaudited)

(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, 2005               | 60,005      | $  (358) | $(20,903) | $(21,261)
|                                |             |          |           |          
|Net income for the three months |             |          |           |          
|ended March 31, 2006            | --          | --       | 37        | 37       
|                                |             |          |           |          
|Partners' deficit at            |             |          |           |          
|March 31, 2006                  | 60,005      | $(358)   | $(20,866) | $(21,224)























































See Accompanying Notes to Financial Statements



















NATIONAL PROPERTY INVESTORS 4

STATEMENTS OF CASH FLOWS

(Unaudited)

(in thousands)





|                                                         |                    |        
|-------------------------------------------------------- | ------------------ | -------
|                                                         | Three Months Ended
|                                                         | March 31,         
|                                                         | 2006               | 2005   
|Cash flows from operating activities:                    |                    |        
|Net income                                               | $    37            | $   287
|Adjustments to reconcile net income to net cash provided |                    |        
|by operating activities:                                 |                    |        
|Depreciation                                             | 358                | 149    
|Amortization of loan costs                               | 11                 | 11     
|Change in accounts:                                      |                    |        
|Receivables and deposits                                 | (61)               | 7      
|Other assets                                             | (60)               | 65     
|Accounts payable                                         | 376                | 154    
|Tenant security deposit liabilities                      | 29                 | (17)   
|Other liabilities                                        | 91                 | 32     
|Due to affiliates                                        | 136                | 35     
|Net cash provided by operating activities                | 917                | 723    
|                                                         |                    |        
|Cash flows used in investing activities:                 |                    |        
|Property improvements and replacements                   | (752)              | (547)  
|                                                         |                    |        
|Cash flows from financing activities:                    |                    |        
|Advances from affiliates                                 | 313                | 40     
|Payments on mortgage note payable                        | (236)              | (224)  
|Net cash provided by (used in) financing activities      | 77                 | (184)  
|                                                         |                    |        
|Net increase (decrease) in cash and cash equivalents     | 242                | (8)    
|Cash and cash equivalents at beginning of period         | 123                | 134    
|Cash and cash equivalents at end of period               | $365               | $126   
|                                                         |                    |        
|Supplemental disclosure of cash flow information:        |                    |        
|Cash paid for interest                                   | $471               | $487   
|Supplemental disclosure of non-cash activity:            |                    |        
|Property improvements and replacements included          |                    |        
|in accounts payable                                      | $208               | $53    



At December 31, 2005 and 2004, approximately $547,000 and $269,000, respectively, of property improvements and replacements were included in accounts payable, and are included in property improvements and replacements at March 31, 2006 and 2005, respectively.









See Accompanying Notes to Financial Statements













NATIONAL PROPERTY INVESTORS 4

NOTES TO FINANCIAL STATEMENTS

(Unaudited)





Note A  Basis of Presentation



The accompanying unaudited financial statements of National Property Investors 4 (the "Partnership" or the "Registrant") have been prepared in accordance with generally accepted accounting principles for interim financial information and with the instructions to Form 10-QSB and Item 310(b) of Regulation S-B. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of NPI Equity Investments, Inc. (the "Managing General Partner"), all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three month period ended March 31, 2006 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2006. For further information, refer to the financial statements and footnotes thereto included in the Partnership's Annual Report on Form 10-KSB for the fiscal year ended December 31, 2005. The Managing General Partner is a subsidiary of Apartment Investment and Management Company ("AIMCO"), a publicly traded real estate investment trust.



Recent Accounting Pronouncement



In May 2005, the Financial Accounting Standards Board issued SFAS No. 154 Accounting Changes and Error Corrections, which replaces APB Opinion No. 20 and SFAS No. 3, and changes the requirements for the accounting for and reporting of a change in accounting principle. This statement is effective for accounting changes and corrections of errors made in fiscal years beginning after December 15, 2005. The Partnership adopted SFAS No. 154 effective January 1, 2006. The adoption of SFAS No. 154 did not have a material effect on the Partnerships financial condition or results of operations.



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 received 5% of gross receipts from the Partnership's property as compensation for providing property management services.  The Partnership paid to such affiliates approximately $107,000 and $93,000 for the three months ended March 31, 2006 and 2005, respectively, which is included in operating expenses.



Affiliates of the Managing General Partner charged the Partnership reimbursement of accountable administrative expenses amounting to approximately $80,000 and $44,000 for the three months ended March 31, 2006 and 2005, respectively, which is included in general and administrative expenses and investment property.  The portion of these reimbursements included in investment property for the three months ended March 31, 2006 and 2005 are fees related to construction management services provided by an affiliate of the Managing General Partner of approximately $42,000 and $10,000, respectively.  At March 31, 2006, approximately $170,000 of accountable administrative expenses were unpaid and are included in due to affiliates on the accompanying balance sheet.



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. There were no such fees for the three months ended March 31, 2006 and 2005.



In addition to the amounts discussed above, as compensation for services rendered in managing the Partnership, the Managing General Partner is entitled to receive Partnership Management Fees in conjunction with distributions of cash from operations, subject to certain limitations. There were no such fees for the three months ended March 31, 2006 and 2005, as there were no distributions from operations.



NPI Equity, on behalf of the Partnership and certain affiliated partnerships, has established a revolving credit facility (the "Partnership Revolver") to be used to fund deferred maintenance and working capital needs of the Partnership and certain other affiliated partnerships in the National Property Investors Partnership Series. The maximum draw available to the Partnership under the Partnership Revolver is $300,000. Loans under the Partnership Revolver will have a term of 365 days, be unsecured and bear interest at the prime rate plus 2% per annum (9.75% at March 31, 2006). The maturity date of any such borrowing accelerates in the event of: (i) the removal of NPI Equity as the managing general partner (whether or not for cause); (ii) the sale or refinancing of the property by the Partnership (whether or not a borrowing under the Partnership Revolver was made with respect to such property); or (iii) the liquidation of the Partnership. During the three months ended March 31, 2006, the Managing General Partner agreed to advance funds in excess of the Partnership Revolver to fund redevelopment work at Village of Pennbrook Apartments and advanced approximately $313,000. During the three months ended March 31, 2005, the Partnership advanced the property approximately $40,000 to fund the redevelopment.  Interest expense for the three months ended March 31, 2006 and 2005 amounted to approximately $117,000 and $10,000, respectively. The balance payable at March 31, 2006 including accrued interest is approximately $5,136,000 and is included in due to affiliates on the accompanying balance sheet. Subsequent to March 31, 2006, the Managing General Partner advanced the Partnership approximately $67,000 to fund the redevelopment at Village of Pennbrook Apartments.



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 three months ended March 31, 2006,  the Partnership was charged by AIMCO and its affiliates approximately  $129,000 for hazard insurance coverage and fees associated with policy claims administration.  Additional charges will be incurred by the Partnership during 2006 as other insurance policies renew later in the year. The Partnership was charged by AIMCO and its affiliates approximately $85,000 for insurance coverage and fees associated with policy claims administration during the year ended December 31, 2005.



Note C  Redevelopment of Property



The Partnership has commenced with a redevelopment project at Village of Pennbrook Apartments, during the three months ended March 31, 2006 the estimated project cost was increased from approximately $6,700,000 to $7,200,000.  The redevelopment project is to consist of major landscaping, exterior upgrades and structural improvements. At March 31, 2006 the project was approximately 84% complete and is currently estimated to be completed during the fourth quarter of 2006.  The project has been financed with operating cash flow and advances from an affiliate of the Managing General Partner which accrue interest at prime plus 2%.



Note D  Contingencies



In March 1998, several putative unit holders of limited partnership units of the Partnership commenced an action entitled Rosalie Nuanes, et al. v. Insignia Financial Group, Inc., et al. (the "Nuanes action") in the Superior Court of the State of California for the County of San Mateo. The plaintiffs named as defendants, among others, the Partnership, its Managing General Partner and several of their affiliated partnerships and corporate entities. The action purported to assert claims on behalf of a class of limited partners and derivatively on behalf of a number of limited partnerships (including the Partnership) that are named as nominal defendants, challenging, among other things, the acquisition of interests in certain Managing General Partner entities by Insignia Financial Group, Inc. ("Insignia") and entities that were, at one time, affiliates of Insignia; past tender offers by the Insignia affiliates to acquire limited partnership units; management of the partnerships by the Insignia affiliates; and the series of transactions which closed on October 1, 1998 and February 26, 1999 whereby Insignia and Insignia Properties Trust, respectively, were merged into AIMCO. The plaintiffs sought monetary damages and equitable relief, including judicial dissolution of the Partnership. In addition, during the third quarter of 2001, a complaint captioned Heller v. Insignia Financial Group (the "Heller action") was filed against the same defendants that are named in the Nuanes action. On or about August 6, 2001, plaintiffs filed a first amended complaint. The Heller action was brought as a purported derivative action, and asserted claims for, among other things, breach of fiduciary duty, unfair competition, conversion, unjust enrichment, and judicial dissolution. On January 28, 2002, the trial court granted defendants motion to strike the complaint.  Plaintiffs took an appeal from this order.



On January 8, 2003, the parties filed a Stipulation of Settlement in proposed settlement of the Nuanes action and the Heller action. On June 13, 2003, the court granted final approval of the settlement and entered judgment in both the Nuanes and Heller actions. On August 12, 2003, an objector ("Objector") filed an appeal (the Appeal) seeking to vacate and/or reverse the order approving the settlement and entering judgment thereto. On May 4, 2004, the Objector filed a second appeal challenging the courts use of a referee and its order requiring Objector to pay those fees.



On March 21, 2005, the Court of Appeals issued opinions in both pending appeals.  With regard to the settlement and judgment entered thereto, the Court of Appeals vacated the trial courts order and remanded to the trial court for further findings on the basis that the state of the record is insufficient to permit meaningful appellate review.  The matter was transferred back to the trial court on June 21, 2005.  With regard to the second appeal, the Court of Appeals reversed the order requiring the Objector to pay referee fees. With respect to the related Heller appeal, on July 28, 2005, the Court of Appeals reversed the trial courts order striking the first amended complaint.



On August 18, 2005, Objector and his counsel filed a motion to disqualify the trial court based on a peremptory challenge and filed a motion to disqualify for cause on October 17, 2005, both of which were ultimately denied and/or struck by the trial court.  On or about October 13, 2005 Objector filed a motion to intervene and on or about October 19, 2005 filed both a motion to take discovery relating to the adequacy of plaintiffs as derivative representatives and a motion to dissolve the anti-suit injunction in connection with settlement.  On November 14, 2005, Plaintiffs filed a Motion For Further Findings pursuant to the remand ordered by the Court of Appeals. Defendants joined in that motion.  On February 3, 2006, the Court held a hearing on the various matters pending before it and has ordered additional
briefing from the parties and Objector.  The parties and Objector submitted one final round of briefing to the Court and the matter has been submitted for the Courts decision.



The Managing General Partner does not anticipate that any costs to the Partnership, whether legal or settlement costs, associated with these cases will be material to the Partnerships overall operations.



AIMCO Properties L.P. and NHP Management Company, both affiliates of the Managing General Partner, are defendants in a lawsuit alleging that they willfully violated the Fair Labor Standards Act (FLSA) by failing to pay maintenance workers overtime for all hours worked in excess of forty per week. The complaint, filed in the United States District Court for the District of Columbia, attempts to bring a collective action under the FLSA and seeks to certify state subclasses in California, Maryland, and the District of Columbia. Specifically, the plaintiffs contend that AIMCO Properties L.P. and NHP Management Company failed to compensate maintenance workers for time that they were required to be "on-call". Additionally, the complaint alleges AIMCO Properties L.P. and NHP Management Company failed to comply with the
FLSA in compensating maintenance workers for time that they worked in excess of 40 hours in a week.   In June 2005 the Court conditionally certified the collective action on both the on-call and overtime issues, which allows the plaintiffs to provide notice of the collective action to all non-exempt maintenance workers from August 7, 2000 through the present.  Notices have been sent out to all current and former hourly maintenance workers. Although 1,049 individuals opted-in to the class the defendants will be challenging the eligibility and timeliness of some. Defendants will have the opportunity to move to decertify the collective action with briefing that commences in August.  Because the court denied plaintiffs motion to certify state subclasses, on September 26, 2005, the plaintiffs filed a class action with the same allegations in the Superior Court of California (Contra Costa County), and on November 5, 2005 in Montgomery County Maryland Circuit Court.  The California case has been stayed, while discovery in the Maryland case proceeds. Although the outcome of any litigation is uncertain, AIMCO Properties, L.P. does not believe that the ultimate outcome will have a material adverse effect on its consolidated financial condition or results of operations. Similarly, the Managing General Partner does not believe that the ultimate outcome will have a material adverse effect on the Partnerships financial condition or results of operations.



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 hazardous substances present on a property. Such laws often impose liability without regard to whether the owner or operator knew of, or was responsible for, the release or presence of the hazardous substances. The presence of, or the failure to manage or remedy properly, hazardous substances 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, the presence of hazardous substances 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 hazardous substances through a licensed disposal or treatment facility. Anyone who arranges for the disposal or treatment of hazardous
substances 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 liable for environmental liabilities or costs associated with its property.



Mold



The Partnership is aware of lawsuits against owners and managers of multifamily properties asserting claims of personal injury and property damage caused by the presence of mold, some of which have resulted in substantial monetary judgments or settlements.  The Partnership has only limited insurance coverage for property damage loss claims arising from the presence of mold and for personal injury claims related to mold exposure.  Affiliates of the Managing General Partner have implemented a national policy and procedures to prevent or eliminate mold from its properties and the Managing General Partner believes that these measures will minimize the effects that mold could have on residents.  To date, the Partnership

has not incurred any material costs or liabilities relating to claims of mold exposure or to abate mold conditions.  Because the law regarding mold is unsettled and subject to change the Managing General Partner can make no assurance that liabilities resulting from the presence of or exposure to mold will not have a material adverse effect on the Partnerships financial condition or results of operations.













ITEM 2.

MANAGEMENT'S DISCUSSION AND ANALYSIS OR PLAN OF OPERATION



The matters discussed in this report contain certain forward-looking statements, including, without limitation, statements regarding future financial performance and the effect of government regulations. Actual results may differ materially from those described in the forward-looking statements and will be affected by a variety of risks and factors including, without limitation: national and local economic conditions; the terms of governmental regulations that affect the Registrant and interpretations of those regulations; the competitive environment in which the Registrant operates; financing risks, including the risk that cash flows from operations may be insufficient to meet required payments of principal and interest; real estate risks, including variations of real estate values and the general economic climate in local markets and competition for tenants in such markets; litigation, including costs associated with prosecuting and defending claims and any adverse outcomes, and possible environmental liabilities. Readers should carefully review the Registrant's financial statements and the notes thereto, as well as the risk factors described in the documents the Registrant files from time to time with the Securities and Exchange Commission.



The Partnership's investment property consists of one apartment complex, Village of Pennbrook Apartments, located in Falls Township, Pennsylvania. The average occupancy was 98% and 88% for the three months ended March 31, 2006 and 2005, respectively. The Managing General Partner attributes the increase in average occupancy to competitive pricing and increased curb appeal as a result of the redevelopment project that is discussed in Liquidity and Capital Resources.



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 which 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 recognized net income of approximately $37,000 for the three months ended March 31, 2006, compared to net income of approximately $287,000 for the three months ended March 31, 2005. The decrease in net income is due to an increase in total expenses, partially offset by an increase in total revenues. Total revenues increased due to increases in both rental and other income. Rental income increased due to an increase in occupancy, partially offset by a decrease in the average rental rate at the Partnerships investment property.  Other income increased primarily due to increases in utility reimbursements, laundry income and recreational facility fees, partially offset by a decrease in lease cancellation fees.



Total expenses increased due to increases in operating, depreciation, interest, and general and administrative expenses. Property tax expense remained relatively constant for the comparable period. Operating expense increased primarily due to increases in utility expenses and insurance expense, as a result of increased hazard insurance premiums. Depreciation expense increased due to property improvements and replacements being placed into service during the past twelve months which are now being depreciated. Interest expense increased due to an increase in interest on advances from affiliates, partially offset by a decrease in interest expense on the
mortgage encumbering the Partnerships investment property due to the payment of scheduled principal payments, which has reduced the average outstanding balance over the past twelve months.



The increase in general and administrative expenses is primarily due to an increase in reimbursements to the Managing General Partner as allowed under the Partnership Agreement. Also included in general and administrative expenses for the three months ended March 31, 2006 and 2005 are 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 March 31, 2006 the Partnership had cash and cash equivalents of approximately $365,000, compared to approximately $126,000 at March 31, 2005. Cash and cash equivalents increased approximately $242,000, from December 31, 2005, due to approximately $917,000 and $77,000 of cash provided by operating and financing activities, respectively, partially offset by approximately $752,000 of cash used in investing activities. Cash provided by financing activities consisted of an advance from an affiliate, partially offset by payments of principal on the mortgage encumbering Village of Pennbrook Apartments. Cash used in investing activities consisted of property improvements and replacements.  The Partnership invests its working capital reserves in interest bearing accounts.



NPI Equity, on behalf of the Partnership and certain affiliated partnerships, has established a revolving credit facility (the "Partnership Revolver") to be used to fund deferred maintenance and working capital needs of the Partnership and certain other affiliated partnerships in the National Property Investors Partnership Series. The maximum draw available to the Partnership under the Partnership Revolver is $300,000. Loans under the Partnership Revolver will have a term of 365 days, be unsecured and bear interest at the prime rate plus 2% per annum (9.75% at March 31, 2006). The maturity date of any such borrowing accelerates in the event of: (i) the removal of NPI Equity as the managing general partner (whether or not for cause); (ii) the sale or refinancing of the property by the Partnership (whether or not a borrowing under the Partnership Revolver was made with respect to such property); or (iii) the liquidation of the Partnership. During the three months ended March 31, 2006, the Managing General Partner agreed to advance funds in excess of the Partnership Revolver to fund redevelopment work at Village of Pennbrook Apartments and advanced approximately $313,000. During the three months ended March 31, 2005, the Partnership advanced the property approximately $40,000 to fund the redevelopment.  Interest expense for the three months ended March 31, 2006 and 2005 amounted to approximately $117,000 and $10,000, respectively. The balance payable at March 31, 2006 including accrued interest is approximately $5,136,000 and is included in due to affiliates on the balance sheet. Subsequent to March 31, 2006, the Managing General Partner advanced the Partnership approximately $67,000 to fund the redevelopment at Village of Pennbrook Apartments.



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. For example, the Sarbanes-Oxley Act of 2002 mandates or suggests additional compliance measures with regard to governance, disclosure, audit and other areas.  In light of these changes, the Partnership expects that it will incur higher expenses related to compliance. Capital improvements planned for the Partnerships property are detailed below.



During the three months ended March 31, 2006, the Partnership completed approximately $413,000 of capital improvements at Village of Pennbrook Apartments primarily arising from the redevelopment of the property. These improvements were funded from operating cash flow and advances from an affiliate of the Managing General Partner. The Partnership regularly evaluates the capital improvement needs
of the property. The Partnership has commenced with a redevelopment project at Village of Pennbrook Apartments, during the three months ended March 31, 2006 the estimated project cost was increased from approximately $6,700,000 to $7,200,000.  The redevelopment project is to consist of major landscaping, exterior upgrades and structural improvements. At March 31, 2006 the project was approximately 84% complete and is currently estimated to be completed during the fourth quarter of 2006.  The project has been financed with operating cash flow and advances from an affiliate of the Managing General Partner which accrue interest at prime plus 2%.  Additional routine capital expenditures are anticipated during 2006.  Such capital expenditures will depend on the physical condition of the property as well as anticipated cash flow generated by the property.



The routine capital expenditures will be incurred only to the extent of cash available from operations, Partnership reserves, or advances from affiliates of the Managing General Partner. 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 potential redevelopment costs referenced above) of the Partnership. The mortgage indebtedness of approximately $26,709,000 is being amortized over 20 years and will mature in September 2021, at which time the mortgage is scheduled to be fully amortized.



The Partnership made no distributions during the three months ended March 31, 2006 and 2005. Future cash distributions will depend on the levels of cash generated from operations, refinancing and/or property sale. The Partnerships cash available for distribution is reviewed on a monthly basis. There can be no assurance that the Partnership will generate sufficient funds from operations after capital expenditures to permit distributions to its partners during the remainder of 2006 or subsequent periods.  As a result of the costs associated with the redevelopment project at the Partnerships investment property, it is not expected that the Partnership will generate sufficient funds from operations to permit distributions until the advances associated with the redevelopment project are satisfied.



Other



In addition to its indirect ownership of the general partner interest in the Partnership, AIMCO and its affiliates owned 47,710 limited partnership units (the "Units") in the Partnership representing 79.51% of the outstanding Units at March 31, 2006. 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 79.51% 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.



Critical Accounting Policies and Estimates



The financial statements are prepared in accordance with accounting principles generally accepted in the United States which require the Partnership to make estimates and assumptions. The Partnership believes that of its significant accounting policies, the following may involve a higher degree of judgment and complexity.



Impairment of Long-Lived Assets



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 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; and changes in tax laws and housing laws, including the enactment of rent control laws or other laws regulating multi-family housing.  Any adverse changes in these factors could cause 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 3.

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 such term is 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.



(b)

Internal Control Over Financial Reporting. There have not been any changes in the Partnerships internal control over financial reporting (as such term is defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) during the fiscal quarter to which this report relates that have materially affected, or are reasonably likely to materially affect, the Partnerships internal control over financial reporting.



PART II - OTHER INFORMATION





ITEM 1.

LEGAL PROCEEDINGS



In March 1998, several putative unit holders of limited partnership units of the Partnership commenced an action entitled Rosalie Nuanes, et al. v. Insignia Financial Group, Inc., et al. (the "Nuanes action") in the Superior Court of the State of California for the County of San Mateo. The plaintiffs named as defendants, among others, the Partnership, its Managing General Partner and several of their affiliated partnerships and corporate entities. The action purported to assert claims on behalf of a class of limited partners and derivatively on behalf of a number of limited partnerships (including the Partnership) that are named as nominal defendants, challenging, among other things, the acquisition of interests in certain Managing General Partner entities by Insignia Financial Group, Inc. ("Insignia") and entities that were, at one time, affiliates of Insignia; past tender offers by the Insignia affiliates to acquire limited partnership units; management of the partnerships by the Insignia affiliates; and the series of transactions which closed on October 1, 1998 and February 26, 1999 whereby Insignia and Insignia Properties Trust, respectively, were merged into AIMCO. The plaintiffs sought monetary damages and equitable relief, including judicial dissolution of the Partnership. In addition, during the third quarter of 2001, a complaint captioned Heller v. Insignia Financial Group (the "Heller action") was filed against the same defendants that are named in the Nuanes action. On or about August 6, 2001, plaintiffs filed a first amended complaint. The Heller action was brought as a purported derivative action, and asserted claims for, among other things, breach of fiduciary duty, unfair competition, conversion, unjust enrichment, and judicial dissolution. On January 28, 2002, the trial court granted defendants motion to strike the complaint.  Plaintiffs took an appeal from this order.



On January 8, 2003, the parties filed a Stipulation of Settlement in proposed settlement of the Nuanes action and the Heller action. On June 13, 2003, the court granted final approval of the settlement and entered judgment in both the Nuanes and Heller actions. On August 12, 2003, an objector ("Objector") filed an appeal (the Appeal) seeking to vacate and/or reverse the order approving the settlement and entering judgment thereto. On May 4, 2004, the Objector filed a second appeal challenging the courts use of a referee and its order requiring Objector to pay those fees.



On March 21, 2005, the Court of Appeals issued opinions in both pending appeals.  With regard to the settlement and judgment entered thereto, the Court of Appeals vacated the trial courts order and remanded to the trial court for further findings on the basis that the state of the record is insufficient to permit meaningful appellate review.  The matter was transferred back to the trial court on June 21, 2005.  With regard to the second appeal, the Court of Appeals reversed the order requiring the Objector to pay referee fees. With respect to the related Heller appeal, on July 28, 2005, the Court of Appeals reversed the trial courts order striking the first amended complaint.



On August 18, 2005, Objector and his counsel filed a motion to disqualify the trial court based on a peremptory challenge and filed a motion to disqualify for cause on October 17, 2005, both of which were ultimately denied and/or struck by the trial court.  On or about October 13, 2005 Objector filed a motion to intervene and on or about October 19, 2005 filed both a motion to take discovery relating to the adequacy of plaintiffs as derivative representatives and a motion to dissolve the anti-suit injunction in connection with settlement.  On November 14, 2005, Plaintiffs filed a Motion For Further Findings pursuant to the remand ordered by the Court of Appeals. Defendants joined in that motion.  On February 3, 2006, the Court held a hearing on the various matters pending before it and has ordered additional briefing from the parties and Objector.  The parties and Objector submitted one final round of briefing to the Court and the matter has been submitted for the Courts decision.



The Managing General Partner does not anticipate that any costs to the Partnership, whether legal or settlement costs, associated with these cases will be material to the Partnerships overall operations.



AIMCO Properties L.P. and NHP Management Company, both affiliates of the Managing General Partner, are defendants in a lawsuit alleging that they willfully violated the Fair Labor Standards Act (FLSA) by failing to pay maintenance workers overtime for all hours worked in excess of forty per week. The complaint, filed in the United States District Court for the District of Columbia, attempts to bring a collective action under the FLSA and seeks to certify state subclasses in California, Maryland, and the District of Columbia. Specifically, the plaintiffs contend that AIMCO Properties L.P. and NHP Management Company failed to compensate maintenance workers for time that they were required to be "on-call". Additionally, the complaint alleges AIMCO Properties L.P. and NHP Management Company failed to comply with the FLSA in compensating maintenance workers for time that they worked in excess of 40 hours in a week.   In June 2005 the Court conditionally certified the collective action on both the on-call and overtime issues, which allows the plaintiffs to provide notice of the collective action to all non-exempt maintenance workers from August 7, 2000 through the present.  Notices have been sent out to all current and former hourly maintenance workers. Although 1,049 individuals opted-in to the class the defendants will be challenging the eligibility and timeliness of some. Defendants will have the opportunity to move to decertify the collective action with briefing that commences in August.  Because the court denied plaintiffs motion to certify state subclasses, on September 26, 2005, the plaintiffs filed a class action with the same allegations in the Superior Court of California (Contra Costa County), and on November 5, 2005 in Montgomery County Maryland Circuit Court.  The California case has been stayed, while discovery in the Maryland case proceeds. Although the outcome of any litigation is uncertain, AIMCO Properties, L.P. does not believe that the ultimate outcome will have a material adverse effect on its consolidated financial condition or results of operations. Similarly, the Managing General Partner does not believe that the ultimate outcome will have a material adverse effect on the Partnerships financial condition or results of operations.



ITEM 5.

OTHER INFORMATION



None.



ITEM 6.

EXHIBITS



See Exhibit Index.













SIGNATURES







In accordance with the requirements of the Exchange Act, the Registrant 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/Martha L. Long           
| | Martha L. Long                    
| | Senior Vice President             
| |                                   
| | By:   /s/Stephen B. Waters        
| | Stephen B. Waters                 
| | Vice President                    
| |                                   
| | Date: May 12, 2006                















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 Exhibit 2.1 to 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 Exhibit 2.2 to 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 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 as Exhibit 3.4a to the Registrant's Form 10-KSB for the year ended December 31, 2005.



10.1

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



10.7

Multifamily Note dated August 30, 2001, by and between National Property Investors 4, a California limited partnership, and GMAC Commercial Mortgage Corporation, a California corporation initially filed as Exhibit 10.7 to the Registrant's Form 10QSB for the quarter ended September 30, 2001 and incorporated herein by reference.



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 the equivalent of the 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.









Exhibit 31.1

CERTIFICATION

I, Martha L. Long, certify that:

1.

I have reviewed this quarterly report on Form 10-QSB of National Property Investors 4;

2.

Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;



3.

Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the small business issuer as of, and for, the periods presented in this report;



4.

The small business issuer's other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the small business issuer and have:



(a)

Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the small business issuer, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;



(b)

Evaluated the effectiveness of the small business issuer's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and



(c)

Disclosed in this report any change in the small business issuer's internal control over financial reporting that occurred during the small business issuer's most recent fiscal quarter (the small business issuer's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the small business issuer's internal control over financial reporting; and



5.

The small business issuer's other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the small business issuer's auditors and the audit committee of the small business issuer's board of directors (or persons performing the equivalent functions):



(a)

All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the small business issuer's ability to record, process, summarize and report financial information; and



(b)

Any fraud, whether or not material, that involves management or other employees who have a significant role in the small business issuer's internal control over financial reporting.

Date:  May 12, 2006

/s/Martha L. Long

Martha L. Long

Senior Vice President of NPI Equity Investments, Inc., equivalent of the chief executive officer of the Partnership







Exhibit 31.2

CERTIFICATION

I, Stephen B. Waters, certify that:

1.

I have reviewed this quarterly report on Form 10-QSB of National Property Investors 4;

2.

Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;



3.

Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the small business issuer as of, and for, the periods presented in this report;



4.

The small business issuer's other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the small business issuer and have:



(a)

Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the small business issuer, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;



(b)

Evaluated the effectiveness of the small business issuer's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and



(c)

Disclosed in this report any change in the small business issuer's internal control over financial reporting that occurred during the small business issuer's most recent fiscal quarter (the small business issuer's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the small business issuer's internal control over financial reporting; and



5.

The small business issuer's other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the small business issuer's auditors and the audit committee of the small business issuer's board of directors (or persons performing the equivalent functions):



(a)

All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the small business issuer's ability to record, process, summarize and report financial information; and



(b)

Any fraud, whether or not material, that involves management or other employees who have a significant role in the small business issuer's internal control over financial reporting.

Date:  May 12, 2006

/s/Stephen B. Waters

Stephen B. Waters

Vice President of NPI Equity Investments, Inc., equivalent of the chief financial officer of the Partnership









Exhibit 32.1





Certification of CEO and CFO

Pursuant to 18 U.S.C. Section 1350,

As Adopted Pursuant to

Section 906 of the Sarbanes-Oxley Act of 2002







In connection with the Quarterly Report on Form 10-QSB of National Property Investors 4 (the "Partnership"), for the quarterly period ended March 31, 2006 as filed with the Securities and Exchange Commission on the date hereof (the "Report"), Martha L. Long, as the equivalent of the Chief Executive Officer of the Partnership, and Stephen B. Waters, as the equivalent of the Chief Financial Officer of the Partnership, each hereby certifies, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to the best of his knowledge:



(1)

The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and



(2)

The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Partnership.



| |                        
| | -----------------------
| | /s/Martha L. Long      
| | Name: Martha L. Long   
| | Date: May 12, 2006     
| |                        
| | /s/Stephen B. Waters   
| | Name: Stephen B. Waters
| | Date: May 12, 2006     





This certification is furnished with this Report pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 and shall not be deemed filed by the Partnership for purposes of Section 18 of the Securities Exchange Act of 1934, as amended.







21