UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    ---------

                                    FORM 10-K

(Mark One)

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

      For the fiscal year ended:   December 31, 2002
                                   -----------------

                                             OR

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

      For the transition period from               to
                                     -------------    -------------

                      Commission file number: 333-74674-15


              CWMBS, Inc., CHL Mortgage Pass-Through Trust 2002-12
               Mortgage Pass-Through Certificates, Series 2002-12
               --------------------------------------------------
             (Exact name of Registrant as specified in its charter)


         Delaware                                      95-4449516
------------------------                    -----------------------------------
(State or other jurisdiction of             (IRS Employer Identification Number)
incorporation or organization)

c/o   Countrywide Home Loans Servicing LP
      4500 Park Granada
      Calabasas, California                               91302
--------------------------------             ------------------------------
(Address of principal executive offices)               (Zip Code)

Registrant's telephone number, including area code:   (818) 225-3000
                                                      --------------

Securities registered pursuant to Section 12(b) of the Act:  None
                                                             ----

Securities registered pursuant to Section 12(g) of the Act:  None
                                                             ----



<PAGE>


Indicate by check mark whether the Registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
Registrant was required to file such reports), and (2) has been subject to
such filing requirements for the past 90 days. Yes X   No
                                                  ---    ---

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K ( ss.229.405 of this chapter) is not contained herein, and
will not be contained, to the best of Registrant's knowledge, in definitive
proxy or information statements incorporated by reference in Part III of this
Form 10-K or any amendment to this Form 10-K. [ ]

Indicate  by check mark  whether  the  registrant  is an  accelerated  filer
(as defined in Rule 12b-2 of the Act. Yes     No X
                                         ---    ---

State the aggregate market value of the voting and non-voting common equity
held by non-affiliates of the Registrant: Not applicable
                                          --------------

Indicate the number of shares outstanding of each of the registrant's classes
of common stock, as of December 31, 2002: Not applicable
                                          --------------


                                      2
<PAGE>


DOCUMENTS INCORPORATED BY REFERENCE

                                     None.

                                *     *     *


     This Annual Report on Form 10-K (the "Report") is filed with respect to
the trust fund entitled CHL Mortgage Pass-Through Trust 2002-12 (the "Trust
Fund") formed pursuant to the pooling and servicing agreement dated as of June
1, 2002 (the "Pooling and Servicing Agreement") among CWMBS, Inc., as
depositor (the "Company"), Countrywide Home Loans, Inc., as seller (the
"Seller"), Countrywide Home Loans Servicing LP, as master servicer (the
"Master Servicer"), and The Bank of New York, as trustee (the "Trustee"), for
the issuance of CWMBS, Inc., Mortgage Pass-Through Certificates, Series
2002-12 (the "Certificates"). Certain information otherwise required to be
included in this Report by the Instructions to Form 10-K has been omitted in
reliance on the relief granted to the Company in CWMBS, Inc. (February 3,
1994) (the "Relief Letter").


                                      3
<PAGE>


                                    PART I


ITEM 1.   BUSINESS

          Not applicable.  See the Relief Letter.

ITEM 2.   PROPERTIES

          Not applicable.  See the Relief Letter.

ITEM 3.   LEGAL PROCEEDINGS

          There were no material pending legal proceedings relating to the
          Trust Fund to which any of the Trust Fund, the Trustee, the Master
          Servicer or the Company was a party or of which any of their
          respective properties was the subject during the fiscal year covered
          by this Report, nor is the Company aware of any such proceedings
          contemplated by governmental authorities.

ITEM 4.   SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS

          No matter was submitted to a vote of Certificateholders, and no
          Certificateholder consent was solicited during the fiscal year
          covered by this Report.


                                       4
<PAGE>


                                    PART II


ITEM 5.   MARKET FOR REGISTRANT'S COMMON EQUITY AND RELATED STOCKHOLDER MATTERS

          (a)   Market Information. There is no established public trading
                market for the Certificates.

          (b)   Holders.  As of December 31, 2002 there were less than 300
                holders of record of the Certificates.

          (c)   Dividends. Not applicable. See the Relief Letter. (Information
                as to distributions to Certificateholders is provided in the
                Registrant's monthly filings on Form 8-K.)

          (d)   Securities Authorized for Issuance Under Equity Compensation
                Plans. Not applicable.

          (e)   Item 701 of Regulation S-K. Not applicable. See the Relief
                Letter.

          (f)   Rule 463 of the Securities Act of 1933. Not applicable. See
                the Relief Letter.

ITEM 6.   SELECTED FINANCIAL DATA

          Not applicable.  See the Relief Letter.

ITEM 7.    MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS

          Not applicable.  See the Relief Letter.

ITEM 7A   QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

          Not applicable.

ITEM 8.   FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

          Not applicable.  See the Relief Letter.

ITEM 9.   CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
          FINANCIAL DISCLOSURE

          None.


                                      5
<PAGE>


                                   PART III


ITEM 10.  DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

          Not applicable.  See the Relief Letter.

ITEM 11.  EXECUTIVE COMPENSATION

          Not applicable.  See the Relief Letter.

ITEM 12.  SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

          Information required by Item 201(d) of Regulation S-K: Not
          applicable.

          Information required by Item 403 of Regulation S-K:

          (a) Not applicable. See the Relief Letter.

          (b) Not applicable. See the Relief Letter.

          (c) Not applicable. See the Relief Letter.

ITEM 13.  CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

          Not applicable.  See the Relief Letter.

ITEM 14.  CONTROLS AND PROCEDURES

          Not applicable. The Registrant is an Asset-Backed Issuer (as defined
          in Exchange Act Rules 13a-14(g) and 15d-14(g)) and is therefore not
          required to disclose information under Item 307 of Regulation S-K.
          See paragraph (c) of Item 307 of Regulation S-K.


                                       6
<PAGE>


                                    PART IV


ITEM 15.  EXHIBITS, FINANCIAL STATEMENT SCHEDULES, AND REPORTS ON FORM 8-K

          (a)  (1)  Pursuant to the Pooling and Servicing Agreement, the Master
                    Servicer is required (i) to deliver an annual statement as
                    to compliance with the provisions of the Pooling and
                    Servicing Agreement and certain other matters (the "Annual
                    Statement of the Master Servicer") and (ii) to cause a firm
                    of independent public accountants to deliver an annual
                    report as to compliance with the servicing provisions of the
                    Pooling and Servicing Agreement (the "Annual Report of the
                    Firm of Accountants"). The Annual Statement of the Master
                    Servicer is attached as Exhibit 99.1 to this Report. The
                    Annual Report of the Firm of Accountants is attached as
                    Exhibit 99.2 to this Report. See Relief Letter.

               (2)  Not applicable.

               (3)  The required exhibits are as follows:

                    o   Exhibit 3(i): Copy of Company's Certificate of
                        Incorporation (Filed as an Exhibit to Registration
                        Statement on Form S-3 (File No. 33-63714)).

                    o   Exhibit 3(ii): Copy of Company's By-laws (Filed as
                        an Exhibit to Registration Statement on Form S-3
                        (File No. 33-63714)).

                    o   Exhibit 4: Pooling and Servicing Agreement (Filed as
                        part of the Registrant's Current Report on Form 8-K
                        filed on October 15, 2002).

                    o   Exhibit 99.1: Annual Statement of the Master Servicer.

                    o   Exhibit 99.2: Annual Report of the Firm of
                        Accountants.

          (b) Current Reports on Form 8-K filed during the last quarter ending
          December 31, 2002:


          Date of Current Report                Item Reported
          ----------------------                -------------

          June 28, 2002              Pooling and Servicing Agreement

          September 25, 2002         Monthly report sent to certificateholders
                                     with the September 2002 distribution


                                      7
<PAGE>


          October 25, 2002           Monthly report sent to certificateholders
                                     with the October 2002 distribution

          November 25, 2002          Monthly report sent to certificateholders
                                     with the November 2002 distribution


          (c) See subparagraph (a)(3) above.

          (d) Not applicable. See the Relief Letter.


                                      8
<PAGE>


                                  SIGNATURES

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

                              CWMBS, INC.,
                              CHL MORTGAGE PASS-THROUGH TRUST, 2002-12,
                              MORTGAGE PASS-THROUGH CERTIFICATES,
                              SERIES 2002-12

                              By:   Countrywide Home Loans Servicing LP,
                                    as Master Servicer*

                              By:   Countrywide GP, Inc.


                              By:   /s/ Joseph M. Candelario
                                    ---------------------------
                                    Name:  Joseph M. Candelario
                                    Title: First Vice President

                              Date: March 27, 2003



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

*     This Report is being filed by the Master Servicer on behalf of the Trust
      Fund. The Trust Fund does not have any officers or directors.


                                       9
<PAGE>


                                 CERTIFICATION
                                 -------------


          I, Richard DeLeo, certify that:

          1. I have reviewed this annual report on Form 10-K, and all reports
          on Form 8-K containing distribution and servicing reports filed in
          respect of periods included in the year covered by this annual
          report, of CWMBS, Inc., CHL Mortgage Pass-Through Trust 2002-12;

          2. Based on my knowledge, the information in these reports, taken as
          a whole, does not contain any untrue statement of a material fact or
          omit to state a material fact necessary to make the statements made,
          in light of the circumstances under which such statements were made,
          not misleading as of the last day of the period covered by this
          annual report;

          3. Based on my knowledge, the distribution or servicing information
          required to be provided to the trustee by the master servicer under
          the pooling and servicing, or similar, agreement, for inclusion in
          these reports is included in these reports;

          4. I am responsible for reviewing the activities performed by the
          master servicer under the pooling and servicing, or similar,
          agreement and based upon my knowledge and the annual compliance
          review required under that agreement, and except as disclosed in the
          reports, the master servicer has fulfilled its obligations under
          that agreement; and

          5. The reports disclose all significant deficiencies relating to the
          master servicer's compliance with the minimum servicing standards
          based upon the report provided by an independent public accountant,
          after conducting a review in compliance with the Uniform Single
          Attestation Program for Mortgage Bankers or similar procedure, as
          set forth in the pooling and servicing, or similar, agreement, that
          is included in these reports.

          In giving the certifications above, I have reasonably relied on
          information provided to me by the following unaffiliated parties:
          The Bank of New York, as Trustee; HSBC Mortgage Corporation;
          National City Mortgage Co.; SunTrust Mortgage, Inc.; and Litton
          Servicing LP.


          Date: March 27, 2003


                                          /s/ Richard De Leo
                                          ------------------
                                          Richard De Leo
                                          Managing Director


                                      10
<PAGE>


      SUPPLEMENTAL INFORMATION TO BE FURNISHED WITH REPORTS FILED PURSUANT TO
SECTION 15(d) OF THE ACT BY REGISTRANTS WHICH HAVE NOT REGISTERED SECURITIES
PURSUANT TO SECTION 12 OF THE ACT.

      No such annual report, proxy statement, form of proxy or other soliciting
material has been sent to Certificateholders. See the Relief Letter.


                                      11
<PAGE>


                                  EXHIBIT INDEX


                                                                    Sequential
Exhibit Document                                                   Page Number
------- --------                                                   -----------


3(i)      Company's Certificate of Incorporation (Filed as an
          Exhibit to Registration Statement on Form S-3 (File
          No. 33-63714))  *

3(ii)     Company's By-laws (Filed as an Exhibit to Registration
          Statement on Form S-3 (File No. 33-63714))  *

4         Pooling and Servicing Agreement (Filed as part of the
          Company's Current Report on Form 8-K filed on October
         15, 2002)  *

99.1      Annual Statement of the Master Servicer...........................13

99.2      Annual Report of the Firm of Accountants..........................15







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

*     Incorporated herein by reference.

                                      12