SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                   FORM 10-K/A
                                 Amendment No.1


(Mark One)

/     x / ANNUAL  REPORT  PURSUANT  TO  SECTION  13 OR  15(d) OF THE  SECURITIES
      EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 1999 or

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


      Commission File No.:   333-37717

    GMAC Commercial Mortgage Securities, Inc.
    Mortgage Pass-Through Certificates Series 1999-C1
    (Exact name of registrant as specified in its charter)



New York                         52-2155294  52-6994909
                                 52-2155295  52-2155297
(State or other jurisdiction     (I.R.S. Employer
 of incorporation or              Identification  No.)
 organization)


c/o Wells Fargo Bank Minnesota, N.A.
11000 Broken Land Parkway
Columbia, Maryland                            21044
(Address of principal executive offices)     (ZIP Code)


Registrant's telephone number, including area code:
     (410) 884-2000

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

     NONE

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

     NONE

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the  preceding 12 months (or for such  shorter  period that the  registrant  was
required  to file  such  reports),  and  (2) has  been  subject  to such  filing
requirements for the past 90 days.

     Yes   X          No ___


This Amendment No. 1 on Form 10-K/A amends Item 14 of the original Annual Report
on Form 10-K (the  "Original  Form 10-K") filed on March 24, 2000,  on behalf of
GMAC Commercial Mortgage  Securities,  Inc. Mortgage  Pass-Through  Certificates
Series 1999-C1 established pursuant to the Pooling and Servicing Agreement among
GMAC Commercial Mortgage Securities, Inc. as Depositor, GMAC Commercial Mortgage
Corporation  as Master  Servicer  and  Special  Servicer,  and Wells  Fargo Bank
Minnesota as Trustee, pursuant to which the GMAC Commercial Mortgage Securities,
Inc.  Mortgage  Pass-Through  Certificates  Series 1999-C1  registered under the
Securities Act of 1933 the ("Certificates") were issued.


Item 14 of the original Form 10K is amended in its entirety to read as follows:

Item 14.  Exhibits, Financial Statement Schedules, and Reports
          on Form 8-K.

          (a) Exhibits

              (99.1) Annual   Independent    Accountants'    Servicing   Reports
                     concerning servicing activities for the year ended December
                     31, 1999.

                    a)  GMAC Commercial Mortgage Corp., as Servicer  <F1>
                    b)  GMAC Commercial Mortgage Corp., as Special Servicer <F1>

              (99.2) Report  of  Management   as  to  Compliance   with  Minimum
                     Servicing Standards for the year ended December 31, 1999.

                    a)  GMAC Commercial Mortgage Corp., as Servicer  <F1>
                    b)  GMAC Commercial Mortgage Corp., as Special Servicer <F1>

              (99.3) Annual  Statements  of  Compliance  under the  Pooling  and
                     Servicing Agreements for the year ended December 31, 1999.

                    a)  GMAC Commercial Mortgage Corp., as Servicer  <F1>
                    b)  GMAC Commercial Mortgage Corp., as Special Servicer <F1>


              (99.4) Aggregate Statement of Principal and
                      Interest Distributions to Certificate Holders. <F2>

          (b)    On October 25, 1999,  November 22, 1999, and December 28, 1999,
                 reports  on Form 8-K  were  filed  by the  Company  in order to
                 provide the statements for the monthly distributions to holders
                 of the  Certificates.  No other  reports  on Form 8-K have been
                 filed  during the last  quarter  of the period  covered by this
                 report.

            (c) Not applicable.

            (d)  Omitted.

<F1>  Filed herewith.
<F2>  Previously filed.

                           SIGNATURE

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



GMAC Commercial Mortgage Securities, Inc.
Mortgage Pass-Through Certificates Series  1999-C1


Signed:   Wells Fargo Bank Minnesota, N.A., as Trustee

By:   Sherri Sharps, Vice president
By:  /s/  Sherri Sharps, Vice president

Dated:  April 6, 2001


Exhibit Index

Exhibit No.

99.1      Annual Independent Accountants' Servicing Reports concerning servicing
          activities for the year ended December 31, 1999.

                    a)  GMAC Commercial Mortgage Corp., as Servicer  <F1>
                    b)  GMAC Commercial Mortgage Corp., as Special Servicer <F1>

99.2      Report of Management as to Compliance with Minimum Servicing Standards
          for the year ended December 31, 1999.

                    a)  GMAC Commercial Mortgage Corp., as Servicer  <F1>
                    b)  GMAC Commercial Mortgage Corp., as Special Servicer <F1>

99.3      Annual  Statements  of  Compliance  under the  Pooling  and  Servicing
          Agreements for the year ended December 31, 1999.

                    a)  GMAC Commercial Mortgage Corp., as Servicer  <F1>
                    b)  GMAC Commercial Mortgage Corp., as Special Servicer <F1>

99.4      Aggregate Statement of Principal and Interest Distributions to
          Certificate Holders.<F2>

<F1>  Filed herewith.
<F2>  Previously filed.