March 29, 2000



United States
Securities and Exchange Commission
Washington, D.C.  20549


RE:   National Property Investors 4
      Form 10-KSB
      File No. 0-10412


To Whom it May Concern:

The  accompanying  Form 10-KSB for the year ended  December 31, 1999 describes a
change in the method of  accounting to  capitalize  exterior  painting and major
landscaping,   which  would  have  been  expensed  under  the  old  policy.  The
Partnership believes that this accounting principle change is preferable because
it  provides a better  matching  of  expenses  with the  related  benefit of the
expenditures and it is consistent with industry practice and the policies of the
Managing General Partner.

Please do not hesitate to contact the undersigned with any questions or comments
that you might have.

Very truly yours,



Stephen Waters
Real Estate Controller

<PAGE>

                  FORM 10-KSB--ANNUAL OR TRANSITIONAL REPORT UNDER

                               SECTION 13 OR 15(d)

                                   Form 10-KSB

(Mark One)
[X]  ANNUAL REPORT UNDER SECTION 13 OR 15(d) OF THE  SECURITIES  EXCHANGE ACT OF
     1934
     [No Fee Required]

                    For the fiscal year ended December 31, 1999

[ ]  TRANSITION  REPORT UNDER SECTION 13 OR 15(d) OF THE  SECURITIES  EXCHANGE
     ACT OF 1934
     [No Fee Required]

                For the transition period from _________to _________

                         Commission file number 0-10412

                           NATIONAL PROPERTY INVESTORS 4
                   (Name of small business issuer 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)

                    Issuer's telephone number (864) 239-1000

           Securities registered under Section 12(b) of the Exchange Act:

                                      None

           Securities registered under Section 12(g) of the Exchange Act:

                            Limited Partnership Units

                                (Title of class)

Check  whether the issuer (1) 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___

Check if there is no disclosure of delinquent  filers in response to Item 405 of
Regulation S-B contained in this form, and no disclosure  will be contained,  to
the best of the  Partnership's  knowledge  in  definitive  proxy or  information
statements  incorporated  by  reference  in Part III of this Form  10-KSB or any
amendment to this Form 10-KSB. [ ]

State issuer's revenues for its most recent fiscal year.  $6,847,000

State the aggregate  market value of the voting  partnership  interests  held by
non-affiliates  computed  by  reference  to the price at which  the  partnership
interests  were sold,  or the average bid and asked  prices of such  partnership
interests as of December 31, 1999. 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

<PAGE>

                                     PART I

Item 1.     Description of Business

National  Property  Investors  4 (the  "Partnership"  or the  "Registrant")  was
organized in July 1980, as a limited  partnership  under the California  Uniform
Limited  Partnership  Act. NPI Equity  Investments,  Inc.  ("NPI  Equity" or the
"Managing  General  Partner"),  a Florida  corporation,  is the Managing General
Partner  of  the  Partnership  and is a  wholly-owned  subsidiary  of  Apartment
Investment and Management  Company  ("AIMCO").  (See "Transfer of Control".) The
Partnership  Agreement provides that the Partnership is to terminate on December
31, 2005, 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.  Description of Property").  Since its initial offering the Partnership
has not  received,  nor are the Limited  Partners  required to make,  additional
capital contributions.

The Registrant  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.

The  real  estate  business  in which  the  Partnership  is  engaged  is  highly
competitive.  There are other  residential  properties within the market area of
the  Registrant's  property.  The number and quality of competitive  properties,
including  those which may be managed by an affiliate  of the  Managing  General
Partner,  in such market area could have a material  effect on the rental market
for the  apartments  at the  Partnership's  property  and the rents  that may be
charged  for  such  apartments.  While  the  Managing  General  Partner  and its
affiliates  own and/or  control a significant  number of apartment  units in the
United  States such units  represent an  insignificant  percentage  of the total
apartment  units in the United  States and  competition  for the  apartments  is
local.

There have been, and it is possible there may be other, Federal, state and local
legislation  and  regulations   enacted   relating  to  the  protection  of  the
environment.  The Partnership is unable to predict the extent,  if any, to which
such new  legislation  or  regulations  might occur and the degree to which such
existing or new legislation or regulations  might adversely  affect the property
owned by the Partnership.

The  Partnership  monitors its property for evidence of  pollutants,  toxins and
other dangerous substances, including the presence of asbestos. In certain cases
environmental  testing has been performed which resulted in no material  adverse
conditions or liabilities.  In no case has the Partnership  received notice that
it is a potentially  responsible party with respect to an environmental clean up
site.


<PAGE>


Both the income and expenses of operating the property owned by the  Partnership
are subject to factors outside of the Partnership's  control, such as changes in
the supply and demand for  similar  properties  resulting  from  various  market
conditions, increases/decreases in unemployment or population shifts, changes in
the  availability of permanent  mortgage  financing,  changes in zoning laws, or
changes in patterns or needs of users. In addition,  there are risks inherent in
owning  and  operating  residential   properties  because  such  properties  are
susceptible  to the  impact of  economic  and other  conditions  outside  of the
control of the Partnership.

A further  description  of the  Partnership's  business  is included in "Item 6.
Management's Discussion and Analysis or Plan of Operation" included in this Form
10-KSB.

Transfer of Control

Pursuant  to a series  of  transactions  which  closed  on  October  1, 1998 and
February 26, 1999,  Insignia Financial Group, Inc. and Insignia Properties Trust
merged into AIMCO, a publicly traded real estate  investment  trust,  with AIMCO
being the surviving  corporation  (the "Insignia  Merger").  As a result,  AIMCO
acquired 100% ownership  interest in the Managing General Partner.  The Managing
General  Partner does not believe that this  transaction  has had or will have a
material effect on the affairs and operations of the Partnership.

Item 2.     Description of Property

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

                                    Date of
Property                            Purchase     Type of Ownership        Use

Village of Pennbrook Apartments     12/15/81  Fee simple, subject to   Apartment
  Falls Township, Pennsylvania                first mortgage           722 units

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.
<TABLE>
<CAPTION>

                          Gross
                         Carrying   Accumulated                           Federal
Property                  Value    Depreciation     Rate      Method     Tax Basis
                             (in thousands)                            (in thousands)
Village of Pennbrook
<S>                       <C>         <C>        <C>                      <C>
  Apartments              $27,234     $20,003    5-27.5 yrs    S/L        $ 4,419
</TABLE>

See  "Item 7.  Financial  Statements,  Notes A and J" for a  description  of the
Partnership's   depreciation   policy  and  change  in   accounting   principle,
respectively.


<PAGE>


Schedule of Property Indebtedness

The  following  table  sets  forth  certain  information  relating  to the  loan
encumbering the Registrant's property.
<TABLE>
<CAPTION>

                    Principal                                               Principal
                   Balance At     Monthly      Stated                        Balance
                   December 31,   Payment     Interest  Period   Maturity    Due At
Property              1999     Interest Only    Rate   Amortized   Date     Maturity
                         (in thousands)                                  (in thousands)
Village of Pennbrook
<S>                  <C>           <C>         <C>        <C>    <C>   <C>   <C>
  Apartments         $19,300       $ 118       7.33%      (1)    11/01/03    $19,300
</TABLE>

(1)   Interest only payments with principle due November 1, 2003.

See "Item 7. Financial  Statements - Note E" for information with respect to the
Registrant's  ability to repay this loan and other  specific  details  about the
loan.

Rental Rates and Occupancy

Average annual rental rates and occupancy for 1999 and 1998 for the property:

                                   Average Annual
                                     Rental Rates                   Average
                                      (per unit)                   Occupancy
 Property                         1999           1998           1999        1998
 Village of Pennbrook
   Apartments                   $9,684          $9,370          94%          94%

As noted under "Item 1.  Description of Business",  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.

Real Estate Taxes and Rates

Real estate taxes and rates in 1999 for the property:

                                              1999              1999
                                             Billing            Rate
       Village of Pennbrook
         Apartments                           $520             4.82%

<PAGE>

Capital Improvements

Village of Pennbrook Apartments

During the twelve  months ended  December 31, 1999,  the  Partnership  completed
approximately   $590,000  of  capital   improvements  at  Village  of  Pennbrook
consisting primarily of structural  improvements,  carpet and vinyl replacement,
appliances,  parking lot improvements,  and heating improvements.  These capital
improvements   were  funded  from  replacement   reserves  and  cash  flow.  The
Partnership  is  currently  evaluating  the  capital  improvement  needs  of the
property for the upcoming year. The minimum amount to be budgeted is expected to
be $300 per unit or $216,600. Additional improvements may be considered and will
depend on the physical condition of the property as well as replacement reserves
and anticipated cash flows generated by the property.

Item 3.     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. in the Superior Court of the State of California
for the County of San Mateo. The plaintiffs  named as defendants,  among others,
the  Partnership,  the Managing  General Partner and several of their affiliated
partnerships  and corporate  entities.  The action  purports to assert claims on
behalf of a class of limited  partners and derivatively on behalf of a number of
limited  partnerships  (including  the  Partnership)  which are named as nominal
defendants,  challenging  the  acquisition  by Insignia  Financial  Group,  Inc.
("Insignia")  and  entities  which  were,  at one time,  affiliates  of Insignia
("Insignia  Affiliates") of interests in certain general partner entities,  past
tender offers by Insignia  Affiliates to acquire limited  partnership units, the
management of partnerships  by Insignia  Affiliates and the Insignia Merger (see
"Item 7. Financial  Statements,  Note B - Transfer of Control").  The plaintiffs
seek monetary damages and equitable relief,  including  judicial  dissolution of
the  Partnership.  On June 25, 1998, the Managing General Partner filed a motion
seeking  dismissal  of the action.  In lieu of  responding  to the  motion,  the
plaintiffs have filed an amended  complaint.  The Managing General Partner filed
demurrers to the amended  complaint which were heard February 1999.  Pending the
ruling on such  demurrers,  settlement  negotiations  commenced.  On November 2,
1999,  the parties  executed and filed a  Stipulation  of  Settlement,  settling
claims,  subject to final court  approval,  on behalf of the Partnership and all
limited partners who own units as of November 3, 1999.  Preliminary  approval of
the  settlement  was obtained on November 3, 1999 from the Superior Court of the
State of  California,  County of San Mateo,  at which time the Court set a final
approval  hearing for December 10, 1999.  Prior to the December 10, 1999 hearing
the Court received various  objections to the settlement,  including a challenge
to the Court's preliminary  approval based upon the alleged lack of authority of
class  plaintiffs'  counsel to enter the  settlement.  On December 14, 1999, the
Managing General Partner and its affiliates  terminated the proposed settlement.
Certain  plaintiffs  have filed a motion to disqualify  some of the  plaintiffs'
counsel in the action.  The Managing  General  Partner does not anticipate  that
costs  associated with this case will be material to the  Partnership's  overall
operations.

Estate of Harry  Schubert v.  National  Property  Investors  4, Civil Action No.
97-09129, Court of Common Pleas of Bucks County, Pennsylvania.  During 1998, the
Plaintiff brought action against the Partnership  alleging that as the result of
carbon monoxide and methane  poisoning due to a  malfunctioning  heating unit in
the  deceased's  apartment at the  Partnership's  property,  the  decedent  lost
consciousness

<PAGE>

for several  hours,  suffered  respiratory  arrest and suffered  other pains and
injuries.  The Plaintiff  alleges breach of contract,  fraud,  violations of the
Unfair Trade Practices and Consumer  Protection Law and negligence.  This matter
is currently in the preliminary stages of discovery.  The Partnership intends to
vigorously defend this matter.

The Partnership is unaware of any pending or outstanding  litigation that is not
of a routine nature arising in the ordinary course of business.

Item 4.     Submission of Matters to a Vote of Security Holders

During the quarter ended  December 31, 1999, no matters were submitted to a vote
of the Unit holders through the solicitation of proxies or otherwise.

<PAGE>

                                     PART II

Item 5. Market for the  Registrant's  Common Equity and Related  Security Holder
        Matters

The Partnership,  a publicly-held  limited partnership,  offered and sold 60,005
limited partnership units aggregating $30,002,500.  As of December 31, 1999, the
Partnership  had 60,005  units  outstanding  held by 1,301  limited  partners of
record. Affiliates of the Managing General Partner own 43,106 units or 71.84% at
December 31, 1999. No public trading market has developed for the Units,  and it
is not anticipated that such a market will develop in the future.

The following table sets forth the distributions made by the Partnership for the
years ended  December  31, 1998 and 1999.  All were  distributions  of cash from
operations  (see  "Item  6.  Management's  Discussion  and  Analysis  or Plan of
Operation" for further details).

                                                    Distributions
                                                              Per Limited
                                          Aggregate (2)     Partnership Unit

          01/01/98 - 12/31/98              $1,297,000            $21.40

          01/01/99 - 12/31/99               4,398,000 (1)         72.56


(1)   $551,000 was accrued at December 31, 1999, and paid in January 2000.

(2)   Distributions were from operations.

Future  cash  distributions  will  depend on the levels of cash  generated  from
operations,  the availability of cash reserves, and the timing of debt maturity,
refinancing,  and/or  property sale. The  Partnership's  distribution  policy is
reviewed on a semi-annual  basis. There can be no assurance,  however,  that the
Partnership  will  generate  sufficient  funds from  operations  after  required
capital expenditures to permit further  distributions to its partners in 2000 or
subsequent periods.

Several tender offers were made by various parties,  including affiliates of the
Managing General Partner,  during the years ended December 31, 1999 and 1998. As
a result of these tender offers,  AIMCO and its affiliates  currently own 43,106
limited  partnership  units  in  the  Partnership  representing  71.84%  of  the
outstanding  units. It is possible that AIMCO or its affiliates will make one or
more additional offers to acquire  additional limited  partnership  interests in
the Partnership  for cash or in exchange for units in the operating  partnership
of AIMCO. Consequently, AIMCO is in a position to influence all voting decisions
with respect to the  Registrant.  Under the Partnership  Agreement,  unitholders
holding a majority of the Units are  entitled  to take action with  respect to a
variety of matters.  When voting on matters,  AIMCO would in all likelihood vote
the Units it  acquired in a manner  favorable  to the  interest of the  Managing
General Partner because of their affiliation with the Managing General Partner.

<PAGE>

Item 6.     Management's Discussion and Analysis or Plan of Operation

The  matters  discussed  in this Form  10-KSB  contain  certain  forward-looking
statements  and  involve  risks and  uncertainties  (including  changing  market
conditions, competitive and regulatory matters, etc.) detailed in the disclosure
contained  in this Form 10-KSB and the other  filings  with the  Securities  and
Exchange  Commission made by the Registrant from time to time. The discussion of
the Registrant's business and results of operations,  including  forward-looking
statements  pertaining to such matter, does not take into account the effects of
any changes to the Registrant's business and results of operation.  Accordingly,
actual   results   could  differ   materially   from  those   projected  in  the
forward-looking  statements as a result of a number of factors,  including those
identified herein.

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

Results of Operations

The Partnership realized net income of approximately $841,000 and $1,158,000 for
the years ended  December 31, 1999 and 1998,  respectively.  The decrease in net
income is  attributable  to an increase in total expenses which more than offset
an increase in total  revenues.  The increase in total revenues is the result of
increased  average  rental rates charged at the property.  The increase in total
expenses is due to an increase in general and administrative expenses, operating
expenses,  and depreciation  expense. The increase in general and administrative
expenses  is  primarily  due to the  increase  in  Partnership  management  fees
associated with the increase in distributions  from operations  during 1999. The
increase in operating  expense is due to increased legal expenses.  The increase
in  depreciation  expense  is the result of capital  improvements  at  Pennbrook
during the past twelve months.

Included in general and administrative  expenses for the year ended December 31,
1999 and 1998, are  reimbursements to the Managing General Partner allowed under
the Partnership Agreement associated with its management of the Partnership.  In
addition,  costs  associated with the quarterly and annual  communications  with
investors  and  regulatory  agencies  and  the  annual  audit  required  by  the
Partnership Agreement are also included.

Effective  January 1, 1999, the Partnership  changed its method of accounting to
capitalize the cost of exterior  painting and major landscaping on a prospective
basis.  The  Partnership  believes  that  this  accounting  principle  change is
preferable  because it provides a better  matching of expenses  with the related
benefit of the  expenditures  and is consistent  with industry  practice and the
policies  of the  Managing  General  Partner.  The effect of this  change in net
income for 1999 was not material.  The cumulative  effect,  had this change been
applied to prior periods, is not material.  The accounting principle change will
not have an  effect on cash  flow,  funds  available  for  distribution  or fees
payable to the Managing General Partner and affiliates.

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,  due to changing  market
conditions,  which  can  result  in the use of  rental  concessions  and  rental
reductions to offset softening market conditions, there is no guarantee that the
Managing General Partner will be able to sustain such a plan.

Capital Resources and Liquidity

At  December  31,  1999,  the  Partnership  had  cash and  cash  equivalents  of
approximately  $1,618,000  compared to approximately  $3,418,000 at December 31,
1998.  Cash and cash  equivalents  decreased  approximately  $1,800,000 from the
Partnership's  previous  year ended  December 31,  1998.  The decrease is due to
approximately  $3,847,000 of cash used in financing activities and approximately
$285,000 of cash used in  investing  activities  which was  partially  offset by
approximately $2,332,000 of cash provided by operating activities.  Cash used in
financing  activities  consisted  of  distributions  to  partners.  Cash used in
investing   activities   consisted   primarily  of  property   improvements  and
replacements  partially  offset  by  net  withdrawals  from  restricted  escrows
maintained by the mortgage lender.  The Partnership  invests its working capital
reserves in a money market account.

The Managing  General  Partner has made available to the  Partnership a $300,000
line of credit. At the present time, the Partnership has no outstanding  amounts
due under this line of credit.  Based on present  plans,  the  Managing  General
Partner does not  anticipate  the need to borrow in the near future.  Other than
cash and cash equivalents,  the line of credit is the Partnership's  only unused
source of liquidity.

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 Registrant and to comply with Federal,  state,
and local  legal and  regulatory  requirements.  The  Partnership  is  currently
evaluating the capital  improvement needs of the property for the upcoming year.
The minimum  amount to be budgeted is expected to be $300 per unit or  $216,600.
Additional  improvements  may be  considered  and will  depend  on the  physical
condition of the property as well as replacement  reserves and anticipated  cash
flows generated by the property.  The capital improvements will be incurred only
if cash is available from operations or from partnership reserves. To the extent
that  such  budgeted  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  current assets are thought to be sufficient for any near-term
needs  (exclusive  of capital  improvements)  of the  Partnership.  The mortgage
indebtedness of approximately  $19,300,000 consists of interest only payments of
approximately  $118,000  at a stated  rate of 7.33%.  The  mortgage  matures  on
November 1, 2003,  with the  principal  due on the maturity  date.  The Managing
General  Partner will attempt to refinance  such remaining  indebtedness  and/or
sell the  property  prior to such  maturity  date.  If the  property  cannot  be
refinanced or sold for a sufficient  amount,  the  Partnership  will risk losing
such property through foreclosure.

Cash distributions from operations of approximately  $3,847,000 were paid during
the year ended December 31, 1999, of which approximately  $3,809,000 was paid to
the limited partners ($63.48 per limited partnership unit). At December 31, 1999
a distribution payable of approximately $551,000  (approximately $545,000 to the
limited  partners  or $9.08  per  limited  partnership  unit)  was  accrued  and
subsequently paid in January 2000. In January 1998, the Partnership  distributed
approximately  $1,297,000  (approximately  $1,284,000  to the limited  partners,
$21.40 per limited  partnership  unit) to the partners from  operations.  Future
cash  distributions will depend on the levels of cash generated from operations,
the  availability  of  cash  reserves  and  the  timing  of the  debt  maturity,
refinancing,  and/or  property sale. The  Partnership's  distribution  policy is
reviewed on a semi-annual  basis. There can be no assurance,  however,  that the
Partnership  will  generate  sufficient  funds from  operations  after  required
capital expenditures to permit further  distributions to its partners in 2000 or
subsequent periods.

Tender Offer

Several tender offers were made by various parties,  including affiliates of the
Managing General Partner,  during the years ended December 31, 1999 and 1998. As
a result of these tender offers,  AIMCO and its affiliates  currently own 43,106
units of limited partnership units in the Partnership representing 71.84% of the
outstanding  units. It is possible that AIMCO or its affiliates will make one or
more additional offers to acquire  additional limited  partnership  interests in
the Partnership  for cash or in exchange for units in the operating  partnership
of AIMCO. Consequently, AIMCO is in a position to influence all voting decisions
with respect to the  Registrant.  Under the Partnership  Agreement,  unitholders
holding a majority of the Units are  entitled  to take action with  respect to a
variety of matters.  When voting on matters,  AIMCO would in all likelihood vote
the Units it  acquired in a manner  favorable  to the  interest of the  Managing
General Partner because of their affiliation with the Managing General Partner.

Year 2000 Compliance

General Description

The Year 2000 issue is the result of computer  programs  being written using two
digits rather than four digits to define the applicable year. The Partnership is
dependent  upon the Managing  General  Partner and its affiliates for management
and  administrative  services  ("Managing  Agent").  Any of the Managing Agent's
computer programs or hardware that had date-sensitive software or embedded chips
might have  recognized  a date using "00" as the year 1900  rather than the year
2000.  This could have resulted in a system failure or  miscalculations  causing
disruptions of operations,  including, among other things, a temporary inability
to process  transactions,  send invoices,  or engage in similar normal  business
activities.

Computer Hardware, Software and Operating Equipment

In 1999,  the Managing  Agent  completed  all phases of its Year 2000 program by
completing  the  replacement  and repair of any  hardware or software  system or
operating  equipment that was not yet Year 2000 compliant.  The Managing Agent's
hardware  and software  systems and its  operating  equipment  are now Year 2000
compliant.  No  material  failure or  erroneous  results  have  occurred  in the
Managing Agent's computer  applications  related to the failure to reference the
Year 2000 to date.

Third Parties

To  date,  the  Managing  Agent  is not  aware of any  significant  supplier  or
subcontractor  (external agent) or financial institution of the Partnership that
has a Year 2000 issue that  would  have a material  impact on the  Partnership's
results of operations,  liquidity or capital  resources.  However,  the Managing
Agent  has no means of  ensuring  or  determining  the Year 2000  compliance  of
external  agents.  At this time, the Managing Agent does not believe that a Year
2000 issue of any  non-compliant  external agent will have a material  impact on
the Partnership's financial position or results of operations.

<PAGE>

Costs

The total cost of the Managing Agent's Year 2000 project was approximately  $3.2
million and was funded from operating cash flows.

Risks Associated with the Year 2000

The Managing  Agent  completed all necessary  phases of its Year 2000 program in
1999,  and did not  experience  system or  equipment  malfunctions  related to a
failure to reference the Year 2000. The Managing  Agent or  Partnership  has not
been  materially  adversely  affected by  disruptions  in the economy  generally
resulting from the Year 2000 issue.

At this  time,  the  Managing  Agent  does not  believe  that the  Partnership's
businesses,  results of  operations  or financial  condition  will be materially
adversely affected by the Year 2000 issue.

Contingency Plans Associated with the Year 2000

The  Managing  Agent has not had to implement  contingency  plans such as manual
workarounds or selecting new relationships for its banking or elevator operation
activities in order to avoid the Year 2000 issue.

<PAGE>

Item 7.     Financial Statements

NATIONAL PROPERTY INVESTORS 4

LIST OF FINANCIAL STATEMENTS


Report of Ernst & Young LLP, Independent Auditors

Balance Sheet - December 31, 1999

Statements of Operations - Years ended December 31, 1999 and 1998

Statements of Changes in Partners'  Deficit - Years ended  December 31, 1999 and
1998

Statements of Cash Flows - Years ended December 31, 1999 and 1998

Notes to Financial Statements


<PAGE>


                 Report of Ernst & Young LLP, Independent Auditors

The Partners
National Property Investors 4


We have audited the accompanying  balance sheet of National Property Investors 4
as of December 31, 1999, 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, 1999.  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 auditing standards generally accepted
in the 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. An audit includes examining, on a test basis, evidence
supporting  the amounts and  disclosures in the financial  statements.  An audit
also includes assessing the accounting principles used and significant estimates
made  by the  Partnership's  management,  as  well  as  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, 1999,  and the results of its  operations and its cash flows for
each of the two years in the period ended December 31, 1999, in conformity  with
accounting principles generally accepted in the United States.

                                                            /s/ERNST & YOUNG LLP

Greenville, South Carolina
February 21, 2000


<PAGE>

                           NATIONAL PROPERTY INVESTORS 4

                                  BALANCE SHEET

                        (in thousands, except unit data)

                                December 31, 1999
<TABLE>
<CAPTION>

Assets:
<S>                                                                         <C>
   Cash and cash equivalents                                                $  1,618
   Receivables and deposits                                                      653
   Restricted escrows                                                            173
   Other assets                                                                  540
   Investment property (Notes E and F):
      Land                                                    $  1,980
      Buildings and related personal property                   25,254
                                                                27,234

      Less accumulated depreciation                            (20,003)        7,231

                                                                            $ 10,215

Liabilities and Partners' Deficit

Liabilities:
   Accounts payable                                                           $   35
   Tenant security deposit liabilities                                           362
   Other liabilities                                                             614
   Distribution payable                                                          551
   Mortgage note payable (Note E)                                             19,300

Partners' Deficit:
   General partner                                             $  (353)
   Limited partners (60,005 units issued and
      outstanding)                                             (10,294)      (10,647)

                                                                            $ 10,215
</TABLE>

                 See Accompanying Notes to Financial Statements


<PAGE>


                           NATIONAL PROPERTY INVESTORS 4

                            STATEMENTS OF OPERATIONS

                        (in thousands, except unit data)
<TABLE>
<CAPTION>

                                                           Years Ended December 31,
                                                              1999         1998
Revenues:
<S>                                                          <C>          <C>
   Rental income                                             $ 6,491      $ 6,361
   Other income                                                  356          351
      Total revenues                                           6,847        6,712

Expenses:
   Operating                                                   2,417        2,224
   General and administrative                                    530          365
   Depreciation                                                1,064          993
   Interest                                                    1,489        1,489
   Property taxes                                                506          483
      Total expenses                                           6,006        5,554

Net income (Note G)                                           $  841      $ 1,158

Net income allocated to general partner (1%)                   $   8         $ 12
Net income allocated to limited partners (99%)                   833        1,146

                                                              $  841      $ 1,158

Net income per limited partnership unit                      $ 13.88      $ 19.10

Distributions per limited partnership unit                   $ 72.56      $ 21.40
</TABLE>


                 See Accompanying Notes to Financial Statements


<PAGE>


                           NATIONAL PROPERTY INVESTORS 4

                     STATEMENTS OF CHANGES IN PARTNERS' DEFICIT
                          (in thousands, except unit data)


<TABLE>
<CAPTION>

                                      Limited
                                     Partnership    General     Limited
                                        Units       Partner     Partners      Total

<S>                                    <C>            <C>       <C>         <C>
Original capital contributions         60,005         $  1      $ 30,003    $ 30,004

Partners' deficit at
  December 31, 1997                    60,005       $ (316)     $ (6,635)   $ (6,951)

Distribution to partners                   --          (13)       (1,284)     (1,297)

Net income for the year ended
  December 31, 1998                        --            12        1,146       1,158

Partners' deficit at
  December 31, 1998                    60,005          (317)      (6,773)     (7,090)

Distributions to partners                  --           (44)      (4,354)     (4,398)

Net income for the year ended
  December 31, 1999                        --             8          833         841

Partners' deficit at
  December 31, 1999                    60,005       $  (353)     $(10,294)   $(10,647)
</TABLE>


                 See Accompanying Notes to Financial Statements


<PAGE>


                           NATIONAL PROPERTY INVESTORS 4

                            STATEMENTS OF CASH FLOWS

                                   (in thousands)

<TABLE>
<CAPTION>

                                                             Years Ended December 31,
                                                                 1999         1998
Cash flows from operating activities:
<S>                                                              <C>         <C>
  Net income                                                     $ 841       $ 1,158
  Adjustments to reconcile net income to net
   cash provided by operating activities:
   Depreciation                                                   1,064          993
   Amortization of loan costs                                        75           75
   Change in accounts:
      Receivables and deposits                                       (7)          17
      Other assets                                                  (41)           4
      Accounts payable                                               22          (57)
      Tenant security deposit liabilities                           (73)          30
      Other liabilities                                             451          (39)

          Net cash provided by operating activities               2,332        2,181

Cash flows from investing activities:

  Net withdrawals from restricted escrows                           305          118
  Property improvements and replacements                           (590)        (597)

          Net cash used in investing activities                    (285)        (479)

Cash flows from financing activities:

  Backup withholding paid to limited partners                        --          (35)
  Distributions to partners                                      (3,847)      (1,297)

          Net cash used in financing activities                  (3,847)      (1,332)

Net (decrease) increase in cash and cash equivalents             (1,800)         370

Cash and cash equivalents at beginning of year                    3,418        3,048

Cash and cash equivalents at end of year                        $ 1,618      $ 3,418

Supplemental information:
  Cash paid for interest                                        $ 1,415      $ 1,415

Supplemental information of non-cash activity:
  Distribution payable                                           $  551        $  --
</TABLE>


                 See Accompanying Notes to Financial Statements

<PAGE>

                           NATIONAL PROPERTY INVESTORS 4

                          Notes to Financial Statements

                                December 31, 1999

Note A - Organization and 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"). The Partnership Agreement
provides  that the  Partnership  is to terminate  on December  31, 2005,  unless
terminated prior to such date.

Use of Estimates

The preparation of financial  statements in conformity  with generally  accepted
accounting principles 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.
Acquisition  fees are  capitalized as a cost of real estate.  In accordance with
"Statement of Financial  Accounting  Standards ("SFAS") No. 121, "Accounting for
the  Impairment of Long-Lived  Assets and for  Long-Lived  Assets to be Disposed
Of", the  Partnership  records  impairment  losses on long-lived  assets used in
operations  when  events and  circumstances  indicate  that the assets  might be
impaired  and the  undiscounted  cash flows  estimated  to be generated by those
assets are less than the carrying  amounts of those  assets.  Costs of apartment
properties  that have  been  permanently  impaired  have  been  written  down to
appraised  value.  No  adjustments  for impairment of value were recorded in the
years ended December 31, 1999 and 1998.

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  accelerated  cost recovery  method is used (1) for real property
over 15 years for  additions  prior to March 16,  1984,  18 years for  additions
after March 15, 1984 and before May 9, 1985,  and 19 years for  additions  after
May 8, 1985, and before  January 1, 1987,  and (2) for personal  property over 5
years for additions  prior to January 1, 1987. As a result of the Tax Reform Act
of 1986, for additions  after December 31, 1986, the modified  accelerated  cost
recovery method is used for  depreciation of (1) real property over 27 1/2 years
and (2) personal property additions over 5 years.

Effective  January 1, 1999, the Partnership  changed its method of accounting to
capitalize the costs of exterior painting and major landscaping (see Note J).

<PAGE>

Cash and Cash Equivalents

Includes cash on hand and in banks and money market accounts.  At certain times,
the amount of cash deposited at a bank may exceed the limit on insured deposits.

Loan Costs

Loan  costs of  approximately  $523,000  are  included  in other  assets  in the
accompanying balance sheet and are being amortized on a straight-line basis over
the  life of the  loan.  At  December  31,  1999,  accumulated  amortization  is
approximately  $231,000.  Amortization  of loan costs is  included  in  interest
expense.

Tenant Security Deposits

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

Replacement Reserve Escrow

Village of Pennbrook  Apartments  maintains a replacement reserve escrow to fund
replacement, refurbishment or repair of improvements to the property pursuant to
the  mortgage  note  documents.  As of December  31,  1999,  the balance in this
account is approximately $173,000.

Fair Value of Financial Statements

Statement of Financial Accounting Standards ("SFAS") No. 107, "Disclosures about
Fair Value of Financial  Instruments",  as amended by SFAS No. 119, "Disclosures
about Derivative Financial Instruments and Fair Value of 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 in the SFAS 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 long term
debt)  approximates  their fair value due to the short  term  maturity  of these
instruments.  The  fair  value  of  the  Partnership's  long  term  debt,  after
discounting the scheduled loan payments to maturity,  approximates  its carrying
balance.

Leases

The Partnership generally leases apartment units for twelve-month terms or less.
The Partnership recognizes income as earned on leases. In addition, the Managing
General Partner's policy is to offer rental concessions during particularly slow
months or in response to heavy  competition from similar  complexes in the area.
Concessions are charged against rental income as incurred.

Allocation of Profits, Gains, and Losses

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

<PAGE>

Segment Reporting

SFAS No. 131, Disclosure about Segments of an Enterprise and Related Information
established  standards  for the way  that  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. It also establishes standards for related disclosures
about products and services, geographic areas, and major customers. See "Note H"
for required disclosure.

Income Taxes

Taxable income or loss of the  Partnership is reported in the income tax returns
of its  partners.  No  provision  for  income  taxes  is made  in the  financial
statements of the Partnership.

Advertising Costs

The Partnership expenses the cost of advertising as incurred.  Advertising costs
of approximately  $89,000 in 1999 and $71,000 for 1998 are charged to expense as
incurred and are included in operating expenses.

Note B - Transfer of Control

Pursuant  to a series  of  transactions  which  closed  on  October  1, 1998 and
February 26, 1999,  Insignia Financial Group, Inc. and Insignia Properties Trust
merged into AIMCO, a publicly traded real estate  investment  trust,  with AIMCO
being the surviving  corporation  (the "Insignia  Merger").  As a result,  AIMCO
acquired 100% ownership  interest in the Managing General Partner.  The Managing
General  Partner does not believe that this  transaction  has had or will have a
material effect on the affairs and operations of the Partnership.

<PAGE>

Note C - Transactions with Affiliated Parties

The  Partnership  has no employees  and is  dependent  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 property management services based on a percentage of revenue and
for  reimbursement of certain  expenses  incurred by affiliates on behalf of the
Partnership.

The following  payments were made to affiliates of the Managing  General Partner
during each of the years ended December 31, 1999 and 1998 (in thousands):

                                                         1999       1998

Property management fees (included in operating         $ 343      $ 330
  expenses)
Reimbursement for services of affiliates
  (included in investment property and operating
  and general and administrative expenses)                122        142
Partnership management fee (included in other
  liabilities and general and administrative              232         26
  expenses)
Non-accountable reimbursement (included in general
  and administrative expenses)                            100        100

During the years ended  December 31, 1999 and 1998,  affiliates  of the Managing
General  Partner  were  entitled  to  receive  5% of  gross  receipts  from  the
Partnership's   property  as  compensation  for  providing  property  management
services.  The Partnership  paid to such affiliates  approximately  $343,000 and
$330,000 for the years ended December 31, 1999 and 1998, respectively.

Affiliates of the Managing General Partner received reimbursement of accountable
administrative expenses amounting to approximately $122,000 and $142,000 for the
years ended December 31, 1999 and 1998,  respectively,  including  approximately
$18,000 and $33,000 of construction  services  reimbursements  in 1999 and 1998,
respectively.

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 the  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 was  entitled to receive  $100,000 in both years
ended December 31, 1999 and 1998.

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 a distribution  of
cash from operations,  subject to certain limitations.  The fee in the amount of
$29,000,  related to the December  1999  operating  distribution  was accrued at
December  31,  1999  and  paid  in  January  2000.  The  fee  in the  amount  of
approximately  $203,000 was paid during 1999 in  conjunction  with the operating
distribution  made  during  the year.  The fee in the  amount  of  approximately
$26,000 was paid January 1998 in  conjunction  with the  operating  distribution
made at that time.

<PAGE>

Several tender offers were made by various parties,  including affiliates of the
Managing General Partner,  during the years ended December 31, 1999 and 1998. As
a result of these tender offers,  AIMCO and its affiliates  currently own 43,106
units of limited partnership units in the Partnership representing 71.84% of the
outstanding  units. It is possible that AIMCO or its affiliates will make one or
more additional offers to acquire  additional limited  partnership  interests in
the Partnership  for cash or in exchange for units in the operating  partnership
of AIMCO. Consequently, AIMCO is in a position to influence all voting decisions
with respect to the  Registrant.  Under the Partnership  Agreement,  unitholders
holding a majority of the Units are  entitled  to take action with  respect to a
variety of matters.  When voting on matters,  AIMCO would in all likelihood vote
the Units it  acquired in a manner  favorable  to the  interest of the  Managing
General Partner because of their affiliation with the Managing General Partner.

The Managing  General  Partner has made available to the  Partnership a $300,000
line of credit. At the present time, the Partnership has no outstanding  amounts
due under this line of credit.  Based on present  plans,  the  Managing  General
Partner does not anticipate the need to borrow in the near future.

Note D - Distributions

Cash distributions from operations of approximately  $3,847,000 were paid during
the year ended December 31, 1999, of which approximately  $3,809,000 was paid to
the limited partners ($63.48 per limited partnership unit). At December 31, 1999
a distribution payable of approximately $551,000  (approximately $545,000 to the
limited  partners  or $9.08  per  limited  partnership  unit)  was  accrued  and
subsequently paid in January 2000. In January 1998, the Partnership  distributed
approximately  $1,297,000  (approximately  $1,284,000  to the limited  partners,
$21.40 per limited partnership unit) to the partners from operations.

Note E - Mortgage Note Payable

The principal terms of mortgage note payable are as follows:
<TABLE>
<CAPTION>

                          Principal     Monthly                           Principal
                         Balance At     Payment     Stated                 Balance
                        December 31,   Including   Interest  Maturity      Due At
Property                    1999       Interest      Rate      Date       Maturity
                             (in thousands)                            (in thousands)
Village of Pennbrook
<S>                        <C>           <C>        <C>      <C>   <C>     <C>
  Apartments               $19,300       $ 118      7.33%    11/01/03      $19,300
</TABLE>

The mortgage payable requires  interest only payments with a balloon payment due
in 2003.

The  mortgage  note  payable  is  non-recourse  and is  secured by pledge of the
Partnership's  rental  property  and by pledge of revenues  from the  investment
property.  Prepayment penalties are imposed if the mortgage note is repaid prior
to  maturity.  Further,  the  property  may  not be  sold  subject  to  existing
indebtedness.

<PAGE>

Note F - Real Estate and Accumulated Depreciation
<TABLE>
<CAPTION>

                                                        Initial Cost
                                                       To Partnership
                                                       (in thousands)
                                                              Buildings        Cost
                                                             and Related    Capitalized
                                                              Personal     Subsequent to
Description                         Encumbrances     Land     Property      Acquisition
                                   (in thousands)                         (in thousands)
Village of Pennbrook Apartments
<S>                                    <C>         <C>         <C>            <C>
  Falls Township, Pennsylvania         $19,300     $ 1,972     $18,245        $ 7,017

</TABLE>


<TABLE>
<CAPTION>

                      Gross Amount At Which Carried
                          At December 31, 1999
                             (in thousands)
                                Buildings
                               And Related
                                Personal             Accumulated     Date    Depreciable
Description             Land    Property    Total    Depreciation  Acquired  Life-Years
                                                    (in thousands)
Village of Pennbrook
<S>                   <C>        <C>       <C>         <C>          <C>      <C>
  Apartments          $ 1,980    $25,254   $27,234     $20,003      12/81    5-27.5 yrs
</TABLE>

<PAGE>

Reconciliation of "Real Estate and Accumulated Depreciation":

                                                    December 31,
                                                 1999          1998
                                                   (in thousands)
Investment Property
Balance at beginning of year                    $26,644       $26,047
    Property improvements                           590           597
Balance at end of year                          $27,234       $26,644

Accumulated Depreciation
Balance at beginning of year                    $18,939       $17,946
    Additions charged to expense                  1,064           993
Balance at end of year                          $20,003       $18,939

The  aggregate  cost of the real  estate  for  Federal  income tax  purposes  at
December  31,  1999  and  1998,  is  approximately  $4,805,000  and  $4,215,000,
respectively. The accumulated depreciation taken for Federal income tax purposes
at  December  31,  1999  and  1998,  is  approximately   $386,000  and  $39,000,
respectively. Due to Insignia Properties, L.P. acquiring over 50% of the limited
partnership  units during 1998, the Partnership  was technically  terminated for
tax purposes.

Note G - Income Taxes

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

                                                December 31,
                                              1999         1998

Net income as reported                       $  841       $ 1,158
Add (deduct):
  Depreciation differences                      717           762
  Prepaid rent                                   49            90
  Other                                         219            (8)

Federal taxable income                      $ 1,826       $ 2,002

Federal taxable income per limited
  partnership unit                          $ 30.12       $ 33.03



<PAGE>



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

                                                      1999

         Partners' deficit as reported              $(10,647)
         Land and buildings                          (22,429)
         Accumulated depreciation                     19,617
         Syndication and distribution costs            3,375
         Other                                           407

         Partners' deficit - Federal tax basis      $ (9,677)

Note H - Segment Information

Description  of the types of products  and  services  from which the  reportable
segment derives its revenues

The  Partnership  has  one  reportable  segment:   residential   property.   The
Partnership's  residential property segment consists of one apartment complex in
Pennsylvania. The Partnership rents apartment units for terms that are typically
twelve months or less.

Measurement of segment profit or loss

The  Partnership  evaluates  performance  based on segment  profit (loss) before
depreciation.  The accounting policies of the reportable segment are the same as
those described in the summary of significant accounting policies.

Factors management used to identify the enterprise's reportable segment

Segment information for the years 1999 and 1998 is shown in the tables below (in
thousands). The "Other" column includes partnership administration related items
and income and expense not allocated to the reportable segment.

                 1999                   Residential     Other      Totals

Rental income                             $ 6,491       $   --    $ 6,491
Other income                                  293           63        356
Interest expense                            1,489           --      1,489
Depreciation                                1,064           --      1,064
General and administrative expense             --          530        530
Segment profit (loss)                       1,308         (467)       841
Total assets                                9,578          637     10,215
Capital expenditures for investment
  property                                    590           --        590

<PAGE>

                 1998                   Residential     Other      Totals

Rental income                             $ 6,361       $   --    $ 6,361
Other income                                  235          116        351
Interest expense                            1,489           --      1,489
Depreciation                                  993           --        993
General and administrative expense             --          365        365
Segment profit (loss)                       1,407         (249)     1,158
Total assets                                9,732        3,089     12,821
Capital expenditures for investment
  property                                    597           --        597

Note I - 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. in the Superior Court of the State of California
for the County of San Mateo. The plaintiffs  named as defendants,  among others,
the  Partnership,  the Managing  General Partner and several of their affiliated
partnerships  and corporate  entities.  The action  purports to assert claims on
behalf of a class of limited  partners and derivatively on behalf of a number of
limited  partnerships  (including  the  Partnership)  which are named as nominal
defendants,  challenging  the  acquisition  by Insignia  Financial  Group,  Inc.
("Insignia")  and  entities  which  were,  at one time,  affiliates  of Insignia
("Insignia  Affiliates") of interests in certain general partner entities,  past
tender offers by Insignia  Affiliates to acquire limited  partnership units, the
management of partnerships  by Insignia  Affiliates and the Insignia Merger (see
"Note B - Transfer  of  Control").  The  plaintiffs  seek  monetary  damages and
equitable relief, including judicial dissolution of the Partnership. On June 25,
1998,  the Managing  General  Partner  filed a motion  seeking  dismissal of the
action.  In lieu of  responding  to the  motion,  the  plaintiffs  have filed an
amended  complaint.  The Managing General Partner filed demurrers to the amended
complaint which were heard February 1999.  Pending the ruling on such demurrers,
settlement negotiations commenced. On November 2, 1999, the parties executed and
filed a  Stipulation  of  Settlement,  settling  claims,  subject to final court
approval, on behalf of the Partnership and all limited partners who own units as
of November 3, 1999.  Preliminary  approval of the  settlement  was  obtained on
November 3, 1999 from the Superior Court of the State of  California,  County of
San Mateo, at which time the Court set a final approval hearing for December 10,
1999.  Prior to the  December  10,  1999  hearing  the  Court  received  various
objections to the settlement,  including a challenge to the Court's  preliminary
approval based upon the alleged lack of authority of class  plaintiffs'  counsel
to enter the settlement.  On December 14, 1999, the Managing General Partner and
its affiliates terminated the proposed settlement. Certain plaintiffs have filed
a motion to  disqualify  some of the  plaintiffs'  counsel  in the  action.  The
Managing  General  Partner does not anticipate  that costs  associated with this
case will be material to the Partnership's overall operations.

Estate of Harry  Schubert v.  National  Property  Investors  4, Civil Action No.
97-09129,  Court of Common Pleas of Bucks  County,  Pennsylvania.  The Plaintiff
brought  action  against the  Partnership  alleging that as the result of carbon
monoxide  and  methane  poisoning  due  to a  malfunctioning  heat  unit  in the
deceased's   apartment  at  the  Partnership's   property,   the  decedent  lost
consciousness for several hours, suffered respiratory arrest, and suffered other
pains and injuries. The Plaintiff alleges breach of contract,  fraud, violations
of the Unfair Trade Practices and Consumer  Protection Law and negligence.  This
matter is currently in the  preliminary  stages of  discovery.  The  Partnership
intends to vigorously defend this matter.

The  Partnership is unaware of any other pending or outstanding  litigation that
is not of a routine nature arising in the ordinary course of business.

Note J - Change in Accounting Principle

Effective  January 1, 1999, the Partnership  changed its method of accounting to
capitalize the cost of exterior  painting and major landscaping on a prospective
basis.  The  Partnership  believes  that  this  accounting  principle  change is
preferable  because it provides a better  matching of expenses  with the related
benefit of the  expenditures  and is consistent  with industry  practice and the
policies  of the  Managing  General  Partner.  The effect of this  change on net
income for 1999 was not material.  The cumulative  effect,  had this change been
applied to prior years, is not material.  The accounting  principle  change will
not have an  effect on cash  flow,  funds  available  for  distribution  or fees
payable to the Managing General Partner and affiliates.


<PAGE>

Item 8.  Changes  in  and  Disagreements  with  Accountants  on  Accounting  and
         Financial Disclosures

         None.


<PAGE>


                                    PART III

Item 9. Directors, Executive Officers, Promoters and Control Persons; Compliance
        with Section 16(a) of the Exchange Act

The Partnership has no officers or directors.  NPI Equity,  the Managing General
Partner,  manages substantially all of the Partnership's affairs and has general
responsibility  in all matters  affecting its  business.  NPI Equity is a wholly
owned subsidiary of AIMCO.

The  name of the  directors  and  executive  officers  of the  Managing  General
Partner,  their age and the nature of all  positions  with NPI Equity  presently
held by them are set forth below. There are no family  relationships  between or
among any officers and directors.

Name                        Age    Position

Patrick J. Foye              42    Executive Vice President and Director

Martha L. Long               40    Senior Vice President and Controller

Patrick J. Foye has been  Executive  Vice President and Director of the Managing
General  Partner  since October 1, 1998.  Mr. Foye has served as Executive  Vice
President  of AIMCO  since May 1998.  Prior to  joining  AIMCO,  Mr.  Foye was a
partner in the law firm of Skadden, Arps, Slate, Meagher & Flom LLP from 1989 to
1998 and was  Managing  Partner  of the  firm's  Brussels,  Budapest  and Moscow
offices from 1992  through  1994.  Mr. Foye is also Deputy  Chairman of the Long
Island  Power   Authority  and  serves  as  a  member  of  the  New  York  State
Privatization  Council.  He received a B.A. from Fordham College and a J.D. from
Fordham University Law School.

Martha L. Long has been Senior Vice  President  and  Controller  of the Managing
General  Partner and AIMCO since October 1998, as a result of the acquisition of
Insignia  Financial  Group,  Inc. From June 1994 until January 1997, she was the
Controller for Insignia, and was promoted to Senior Vice President - Finance and
Controller in January 1997,  retaining that title until October 1998.  From 1988
to June 1994,  Ms. Long was Senior Vice  President and  Controller for The First
Savings Bank, FSB in Greenville, South Carolina.

Based solely upon a review of Forms 3 and 4 and amendments  thereto furnished to
the Registrant  under Rule 16a-3(e) during the  Registrant's  most recent fiscal
year and Forms 5 and amendments thereto furnished to the Registrant with respect
to its most recent  fiscal year,  the  Registrant  is not aware of any director,
officer,  beneficial  owner of more than ten  percent  of the  units of  limited
partnership interest in the Registrant that failed to file on a timely basis, as
disclosed in the above Forms,  reports required by section 16(a) of the Exchange
Act during the most recent  fiscal year or prior fiscal years except as follows:
AIMCO and its joint  filers  failed to timely file a Form 4 with  respect to its
acquisition of Units.

Item 10.    Executive Compensation

Neither the director nor the officers of the Managing  General Partner  received
any remuneration from the Registrant.


<PAGE>


Item 11.    Security Ownership of Certain Beneficial Owners and Management

Except as noted below, as of December 31, 1999, no person or entity was known to
own of  record  or  beneficially  more  than  five  percent  of the Units of the
Partnership.

                                             Number of         Percent
                                               Units          of Total
Insignia Properties, 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.                          6,129          10.22%
  (an affiliate of AIMCO)

Insignia Properties,  L.P. and IPLP Acquisition I, LLC are indirectly ultimately
owned by AIMCO.  Their  business  address is 55 Beattie  Place,  Greenville,  SC
29602.

AIMCO  Properties,  L.P.  is  indirectly  ultimately  controlled  by AIMCO.  Its
business address is 2000 Colorado Boulevard, Denver, CO 80222.

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

Item 12.    Certain Relationships and Related Transactions

The  Partnership  has no employees  and is  dependent  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 property  management  based on a  percentage  of revenue and for
reimbursement  of  certain  expenses  incurred  by  affiliates  on behalf of the
Partnership.

The following  payments were made to affiliates of the Managing  General Partner
during each of the years ended December 31, 1999 and 1998 (in thousands):

                                                    1999       1998
                                                     (in thousands)
Property management fees                            $343       $330
Reimbursement for services of affiliates             122        142
Partnership management fee                           232         26
Non-accountable reimbursement                        100        100

During the years ended  December 31, 1999 and 1998,  affiliates  of the Managing
General  Partner  were  entitled  to  receive  5% of  gross  receipts  from  the
Partnership's  residential  property  as  compensation  for  providing  property
management  services.  The  Registrant  paid  to such  affiliates  approximately
$343,000  and  $330,000  for  the  years  ended  December  31,  1999  and  1998,
respectively.

Affiliates of the Managing General Partner received reimbursement of accountable
administrative expenses amounting to approximately $122,000 and $142,000 for the
years ended December 31, 1999 and 1998,  respectively,  including  approximately
$18,000 and $33,000 of construction  services  reimbursements  in 1999 and 1998,
respectively.


<PAGE>


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 the  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 was entitled to receive $100,000 in 1999.

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 a distribution  of
cash from operations,  subject to certain limitations.  The fee in the amount of
$29,000,  related to the December  1999  operating  distribution  was accrued at
December  31,  1999  and  paid  in  January  2000.  The  fee  in the  amount  of
approximately  $203,000 was paid during 1999 in  conjunction  with the operating
distribution  made  during  the year.  The fee in the  amount  of  approximately
$26,000 was paid January 1998 in  conjunction  with the  operating  distribution
made at that time.

Several tender offers were made by various parties,  including affiliates of the
Managing General Partner,  during the years ended December 31, 1999 and 1998. As
a result of these tender offers,  AIMCO and its affiliates  currently own 43,106
units of limited partnership units in the Partnership representing 71.84% of the
outstanding  units. It is possible that AIMCO or its affiliates will make one or
more additional offers to acquire  additional limited  partnership  interests in
the Partnership  for cash or in exchange for units in the operating  partnership
of AIMCO. Consequently, AIMCO is in a position to influence all voting decisions
with respect to the  Registrant.  Under the Partnership  Agreement,  unitholders
holding a majority of the Units are  entitled  to take action with  respect to a
variety of matters.  When voting on matters,  AIMCO would in all likelihood vote
the Units it  acquired in a manner  favorable  to the  interest of the  Managing
General Partner because of their affiliation with the Managing General Partner.

The Managing  General  Partner has made available to the  Partnership a $300,000
line of credit. At the present time, the Partnership has no outstanding  amounts
due under this line of credit.  Based on present  plans,  the  Managing  General
Partner does not anticipate the need to borrow in the near future.


<PAGE>


Item 13.  Exhibits and Reports on Form 8-K

     (a)  Exhibits:

          Exhibit 18, Independent  Accountants'  Preferability Letter for Change
          in Accounting Principle, is filed as an exhibit to this report.

          Exhibit 27,  Financial Data  Schedule,  is filed as an exhibit to this
          report.

     (b)  Reports on Form 8-K filed in the fourth quarter of calendar year 1999:

          None.


<PAGE>


                                   SIGNATURES

In accordance  with Section 13 or 15(d) of the Exchange Act, the  Registrant has
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/Patrick J. Foye
                                          Patrick J. Foye
                                          Executive Vice President

                                    By:   /s/Martha L. Long
                                          Martha L. Long
                                          Senior Vice President
                                          and Controller

                                    Date:


In  accordance  with the Exchange  Act, this report has been signed below by the
following  persons on behalf of the Partnership and in the capacities and on the
dates indicated.

/s/Patrick J. Foye      Executive Vice President      Date:
Patrick J. Foye         and Director


/s/Martha L. Long       Senior Vice President         Date:
Martha L. Long          and Controller

<PAGE>


                                  EXHIBIT INDEX

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.

2.4  Agreement  and Plan of Merger,  dated as of October 1, 1998, by and between
     AIMCO and IPT shown as Exhibit 2.1 in 8-K dated as of October 1, 1988.

2.5  Master  Indemnity  Agreement  dated as of August 17, 1995,  incorporated by
     reference to Exhibit 2.5 to Form 8-K filed by Insignia 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).

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.

10.4 Property  Management  Agreement  dated June 21,  1991,  by and  between the
     Partnership and NPI Management incorporated by reference to Exhibit 10.4 to
     the  Partnership's  Annual Report on Form 10-K for the year ended  December
     31, 1991.

10.5 Multifamily  Note dated  September 30, 1996, by and between the Partnership
     and Lehman Brothers Holding, Inc. for the Village of Pennbrook incorporated
     by  reference to Exhibit 10.5 to the  Partnership's  Annual  Report on Form
     10-K for the year ended December 31, 1996.

10.6 Multifamily Note dated November 1, 1996, by and between the Partnership and
     Lehman Brothers Holding, Inc. for the Village of Pennbrook  incorporated by
     reference to Exhibit 10.6 to the  Partnership's  Annual Report on Form 10-K
     for the year ended December 31, 1991.


<PAGE>


16   Letter dated December 8, 1997,  from the  Registrant's  former  independent
     accountant  regarding  its  concurrence  with  the  statements  made by the
     Registrant in this Current Report.

18   Independent  Accountants'  Preferability  Letter for  Change in  Accounting
     Principle.

27   Financial Data Schedule.


<PAGE>
                                                                      Exhibit 18



February 7, 2000


Mr. Patrick J. Foye
Executive Vice President
NPI Equity Investments, Inc.
Managing General Partner of National Property Investors 4
55 Beattie Place
P.O. Box 1089
Greenville, South Carolina 29602

Dear Mr. Foye:

Note J of Notes to the  Financial  Statements of National  Property  Investors 4
included in its Form  10-KSB for the year ended  December  31, 1999  describes a
change in the method of  accounting to  capitalize  exterior  painting and major
landscaping,  which  would have been  expensed  under the old  policy.  You have
advised us that you believe  that the change is to a  preferable  method in your
circumstances because it provides a better matching of expenses with the related
benefit of the expenditures and is consistent with policies currently being used
by your industry and conforms to the policies of the Managing General Partner.

There are no authoritative criteria for determining a preferable method based on
the particular circumstances; however, we conclude that the change in the method
of accounting  for exterior  painting and major  landscaping is to an acceptable
alternative  method which,  based on your business  judgment to make this change
for the reasons cited above, is preferable in your circumstances.

                                                               Very truly yours,
                                                            /s/Ernst & Young LLP