1
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                   SCHEDULE TO

        TENDER OFFER STATEMENT UNDER SECTION 14(D)(1) OR 13(E)(1) OF THE
                         SECURITIES EXCHANGE ACT OF 1934
                                (AMENDMENT NO. )
                                       AND
                                  SCHEDULE 13D
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                                (AMENDMENT NO. 5)


                  Riverside Park Associates Limited Partnership
- --------------------------------------------------------------------------------
                        (Name of Subject Company (Issuer))

                        AIMCO Properties, L.P. -- Offeror
- --------------------------------------------------------------------------------
            (Names of Filing Persons (Identifying Status as Offeror,
                            Issuer or Other Person))

                            Limited Partnership Units
- --------------------------------------------------------------------------------
                           (Title of Class Securities)

                                      None
- --------------------------------------------------------------------------------
                       (CUSIP Number of Class Securities)

                                 Patrick J. Foye
                   Apartment Investment And Management Company
                           Colorado Center, Tower Two
                   2000 South Colorado Boulevard, Suite 2-1000
                             Denver, Colorado 80222
                                 (303) 757-8101

- --------------------------------------------------------------------------------
            (Name, address, and telephone numbers of person authorized
       to receive notices and communications on behalf of filing persons)

                                    Copy To:

                              Jonathan L. Friedman
                    Skadden, Arps, Slate, Meagher & Flom LLP
                       300 South Grand Avenue, 34th Floor
                          Los Angeles, California 90071
                                 (213) 687-5000



   2

                            Calculation of Filing Fee



                                                        
Transaction valuation*                                     Amount of filing fee
- ----------------------                                     --------------------
$  9,997,432.90                                            $  1,999.49


*        For purposes of calculating the fee only. This amount assumes the
         purchase of 280.15 units of limited partnership interest of the subject
         partnership for $35,686 per unit. The amount of the filing fee,
         calculated in accordance with Section 14(g)(1)(B)(3) and Rule 0-11(d)
         under the Securities Exchange Act of 1934, as amended, equals 1/50th of
         one percent of the aggregate of the cash offered by the bidder.

[ ]      Check the box if any part of the fee is offset as provided by Rule
         0-11(a)(2) and identify the filing with which the offsetting fee was
         previously paid. Identify the previous filing by registration
         statement number, or the Form or Schedule and the date of its filing.

Amount Previously Paid:                          Filing Party:
                       ---------------------                  ------------------

Form or Registration No.:                             Date Filed:
                         -------------------                     ---------------

                      -----------------------------------

[ ] Check the box if the filing relates solely to preliminary communications
made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the
statement relates:

[X] third-party tender offer subject to Rule 14d-1

[ ] issuer tender offer subject to Rule 13e-4

[ ] going-private transaction subject to Rule 13e-3

[X] amendment to Schedule 13D under Rule 13d-2

Check the following box if the filing is a final amendment reporting the results
of the tender offer: [ ]



                                        2
   3

CUSIP No.   NONE

1.       NAME OF REPORTING PERSONS
         S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only)

                  AIMCO PROPERTIES, L.P.
                  84-1275721

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF GROUP
                                                                     (a)     [ ]
                                                                     (b)     [X]
3.       SEC USE ONLY

4.       SOURCE OF FUNDS

                  WC, BK

5.       (CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
         ITEMS 2(d) OR 2(e))                                                 [ ]

6.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON

         7.       SOLE VOTING POWER
                           --

         8.       SHARED VOTING POWER
                  83.42

         9.       SOLE DISPOSITIVE POWER
                           --

         10.      SHARED DISPOSITIVE POWER
                  83.42

11.      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                  83.42

12.      CHECK IF THE AGGREGATE AMOUNT IN ROW (7) EXCLUDES CERTAIN SHARES
                                                                             [ ]

13.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (7)

                  Approximately 14.7%

14.      TYPE OF REPORTING PERSON

                  PN



                                        3
   4

CUSIP No.   NONE

1.       NAME OF REPORTING PERSONS
         S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only)

                  AIMCO-GP, INC.

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF GROUP
                                                                     (a)     [ ]
                                                                     (b)     [X]
3.       SEC USE ONLY

4.       SOURCE OF FUNDS

                  Not Applicable

5.       (CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
         ITEMS 2(d) OR 2(e))                                                 [ ]

6.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON

         7.       SOLE VOTING POWER
                           --

         8.       SHARED VOTING POWER
                  83.42

         9.       SOLE DISPOSITIVE POWER
                           --

         10.      SHARED DISPOSITIVE POWER
                  83.42

11.      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                  83.42

12.      CHECK IF THE AGGREGATE AMOUNT IN ROW (7) EXCLUDES CERTAIN SHARES
                                                                             [ ]

13.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (7)

                    Approximately 14.7%

14.      TYPE OF REPORTING PERSON

                  CO



                                        4
   5

CUSIP No.   NONE

1.       NAME OF REPORTING PERSONS
         S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (entities only)

                  APARTMENT INVESTMENT AND MANAGEMENT COMPANY
                  84-129577

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF GROUP
                                                                     (a)     [ ]
                                                                     (b)     [X]
3.       SEC USE ONLY

4.       SOURCE OF FUNDS

                  Not Applicable

5.       (CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
         ITEMS 2(d) OR 2(e))                                                 [ ]

6.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  Maryland

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON

         7.       SOLE VOTING POWER
                  200.6638

         8.       SHARED VOTING POWER
                  83.4200

         9.       SOLE DISPOSITIVE POWER
                  200.6638

         10.      SHARED DISPOSITIVE POWER
                  83.4200

11.      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                  284.0883

12.      CHECK IF THE AGGREGATE AMOUNT IN ROW (7) EXCLUDES CERTAIN SHARES
                                                                             [ ]

13.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (7)

                     Approximately 50.00%

14.      TYPE OF REPORTING PERSON

                  CO



                                        5
   6

             TENDER OFFER STATEMENT/ AMENDMENT NO. 5 TO SCHEDULE 13D

                  This Statement (the "Statement") constitutes (a) the Tender
Offer Statement on Schedule TO of AIMCO Properties, L.P. (the "AIMCO OP"),
relating to an offer to purchase units of limited partnership interest ("Units")
of Riverside Park Associates Limited Partnership (the "Partnership"); and (b)
Amendment No. 5 to the Schedule 13D (the "Schedule 13D") originally filed with
the Securities and Exchange Commission (the "Commission") on May 14, 1999, by
Apartment Investment and Management Company ("AIMCO"), AIMCO-GP, Inc.
("AIMCO-GP") and AIMCO OP as amended by (i) Amendment No. 1, filed with the
Commission on June 29, 1999, by AIMCO, AIMCO-GP and AIMCO OP, (ii) Amendment No.
2, filed with the Commission on July 9, 1999, by AIMCO, AIMCO-GP and AIMCO OP,
(iii) Amendment No. 3, filed with the Commission on July 16, 1999, by AIMCO,
AIMCO-GP, and AIMCO OP and (iv) Amendment No. 4, filed with the Commission on
August 6, 1999, by AIMCO, AIMCO-GP and AIMCO OP.

                       -----------------------------------

                  The information in the "Offer to Purchase" of AIMCO
Properties, L.P., dated May 15, 2000 (the "Offer"), Exhibit (a)(1) hereto, is
incorporated herein by reference in answer to all of the Items of this Schedule
TO except as otherwise set forth below:

Item 3. Identity and Background of Filing Person.

                  (a) This Statement is being filed by AIMCO Properties, L.P., a
Delaware limited partnership, and, insofar as this Statement constitutes
Amendment No. 5 to the Schedule 13D, by AIMCO Properties, L.P., a Delaware
limited partnership, AIMCO-GP, Inc., a Delaware corporation, Apartment
Investments and Management Company, a Maryland corporation (the "Reporting
Person"). The principal business of the Reporting Person is the ownership,
acquisition, development, expansion and management of multi-family apartment
properties. The principal executive offices and telephone number of the
Reporting Person are located at Colorado Center, Tower Two, 2000 South Colorado
Boulevard, Suite 2-1000, Denver, Colorado 80222; (303) 757-8101.

                  During the last five years, none of the Reporting Person nor,
to the best of its knowledge, any of the persons listed in Annex I to the Offer
(i) has been convicted in a criminal proceeding (excluding traffic violations or
similar misdemeanors) or (ii) was a party to a civil proceeding of a judicial or
administrative body of competent jurisdiction and as a result of such proceeding
was or is subject to a judgment, decree or final order enjoining further
violations of or prohibiting activities subject to federal or state securities
laws or finding any violation with respect to such laws.

Item 5. Past Contacts, Transactions, Negotiations and Agreements.

                  Except as described in the Offer, none of the events set forth
in Item 1005(b) of Regulation S-K has occurred.

Item 6. Purposes of the Transaction and Plans or Proposals.

                  Except as set forth in the Offer, none of the events set forth
in Item 1006 (c) of Regulations S-K is planned, proposed or being negotiated.



                                        6
   7

Item 7. Source and Amount of Funds or Other Consideration.

                  Except as set forth in the Offer, there are no alternative
plans to finance the tender offer and no plans to repay any borrowed funds used
in the tender offer.

Item 8. Interest in Securities of the Subject Company.

         (AIMCO) directly owns 200.6638 Units and AIMCO OP directly owns 83.42
Units, representing 35.3 and 14.7% (aggregating 50%), of the outstanding Units
based on the 568.29 Units outstanding at December 31, 1999.

         AIMCO-GP and AIMCO may be deemed to beneficially own the Units directly
owned by AIMCO OP by each of their relationship with AIMCO OP. AIMCO-GP is the
general partner of AIMCO OP (owning approximately 1% of the total equity
interests). AIMCO-GP is a wholly owned subsidiary of AIMCO.

         Accordingly, for purposes of this Statement: (i) AIMCO OP is reporting
that it shares the power to vote or direct the power to vote and the power to
dispose or direct the disposition of the 83.42 Units directly by it; (ii)
AIMCO-GP is reporting that it shares the power to vote or direct the disposition
of the 84.32 Units owned by AIMCO OP; and (iii) AIMCO is reporting that it
shares the power to vote or direct the vote and the power to dispose or direct
the disposition of the 83.42 Units directly owned by AIMCO-GP, and it has the
sole power to vote or direct the power to vote and the sole power to dispose or
direct the disposition of the 200.6638 Units directly owned by it.

Item 10. Financial Statements.

         The financial statements included in AIMCO OP's Annual Report on Form
10-K for the year ended December 31, 1999, which are listed on the Index to
Financial Statements on page F-1 of such Report, are incorporated herein by
reference. Such report may be inspected at the public reference facilities
maintained by the Commission at Judiciary Plaza, 450 Fifth Street, N.W.,
Washington, D.C. 20549; Citicorp Center, 500 West Madison Street, Chicago,
Illinois 60661; and 7 World Trade Center, 13th Floor, New York, New York 10048.
Copies of such material can also be obtained from the Public Reference Room of
the Commission in Washington, D.C. at prescribed rates and from the Commission's
web site at www.sec.gov.

Item 12. Exhibits.

         (a)(1)    Offer to Purchase, dated May 15, 2000

         (a)(2)(i) Letter of Transmittal and related Instructions (Annex II to
                   Exhibit (a)(1).)

         (a)(2)(ii)Acknowledgment and Agreement

         (a)(3)    Letter, dated May 15, 2000, from AIMCO OP to the limited
                   partners of the Partnership

         (b)(1)    Credit Agreement (Secured Revolving Credit Facility), dated
                   as of August 16, 1999, among AIMCO Properties, L.P., Bank of
                   America, Bank Boston, N.A., and First Union National Bank.
                   (Exhibit 10.1 to AIMCO's Current Report on Form 8-K, dated
                   August 16, 1999, is incorporated herein by this reference.)

         (b)(2)    Amended and Restated Credit Agreement, dated as of March 15,
                   2000, among AIMCO Properties, L.P., Bank of America, Bank
                   Boston, N.A., and First Union National Bank. (Exhibit 10.20
                   to AIMCO Properties, L.P.'s Annual Report on Form 10-K for
                   the year ended December 31, 1999, is incorporated herein by
                   this reference.)

         (b)(3)    First Amendment to $345,000,000 Amended and Restated Credit
                   Agreement, dated as of April 14, 2000, among AIMCO
                   Properties, L.P., Bank of America, as



                                       7
   8

                   Administrative Agent, and U.S. Bank National Association, as
                   Lender. (Exhibit 10.4 to AIMCO's Current Report on Form 10-Q
                   for quarter ended March 31, 2000, is incorporated herein by
                   this reference.)

         (d)       Not applicable.

         (g)       Not applicable.

         (h)       Not applicable.

         (z)(1)    Agreement of Joint Filing, dated May 15, 2000, among AIMCO,
                   AIMCO-GP and AIMCO OP.

Item 13. Information Required by Schedule 13E-3.

                  Not applicable.



                                       8
   9

                                    SIGNATURE

                  After due inquiry and to the best of my knowledge and belief,
I certify that the information set forth in this statement is true, complete and
correct.


Date May 15, 2000                      AIMCO PROPERTIES, L.P.

                                       By: AIMCO-GP, INC.
                                             (General Partner)

                                       By: /s/Patrick J. Foye
                                          --------------------------------------
                                          Executive Vice President

                                       AIMCO-GP, INC.

                                       By: /s/Patrick J. Foye
                                          --------------------------------------
                                          Executive Vice President

                                       APARTMENT INVESTMENT AND
                                       MANAGEMENT COMPANY

                                       By: /s/Patrick J. Foye
                                          --------------------------------------
                                          Executive Vice President



                                       9
   10

                                  EXHIBIT INDEX




EXHIBIT
  NO.                                 DESCRIPTION
- -------                               -----------
               
     (a)(1)       Offer to Purchase, dated May 15, 2000

     (a)(2)(i)    Letter of Transmittal and related Instructions (Annex II to
                  Exhibit (a)(1).)

     (a)(2)(ii)   Acknowledgment and Agreement

     (a)(3)       Letter, dated May 15, 2000, from AIMCO OP to the limited
                  partners of the Partnership

     (b)(1)       Credit Agreement (Secured Revolving Credit Facility), dated as
                  of August 16, 1999, among AIMCO Properties, L.P., Bank of
                  America, Bank Boston, N.A., and First Union National Bank.
                  (Exhibit 10.1 to AIMCO's Current Report on Form 8-K, dated
                  August 16, 1999, is incorporated herein by this reference.)

     (b)(2)       Amended and Restated Credit Agreement, dated as of March 15,
                  2000, among AIMCO Properties, L.P., Bank of America, Bank
                  Boston, N.A., and First Union National Bank. (Exhibit 10.20 to
                  AIMCO Properties, L.P.'s Annual Report on Form 10-K for the
                  year ended December 31, 1999, is incorporated herein by this
                  reference.)

     (b)(3)       First Amendment to $345,000,000 Amended and Restated Credit
                  Agreement, dated as of April 14, 2000, among AIMCO Properties,
                  L.P., Bank of America, as Administrative Agent, and U.S. Bank
                  National Association, as Lender. (Exhibit 10.4 to AIMCO's
                  Current Report on Form 10-Q for quarter ended March 31, 2000,
                  is incorporated herein by this reference.)

     (d)          Not applicable.

     (g)          Not applicable.

     (h)          Not applicable.

     (z)(1)       Agreement of Joint Filing, dated May 15, 2000, among AIMCO,
                  AIMCO-GP and AIMCO OP.