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

               [ ]    Transition Report Pursuant to Section 13 or 15(d) of
                      the Securities Exchange Act of 1934 (No Fee Required)

                   For the Fiscal Year Ended December 31, 2005

                            Commission file numbers:
                                   333-109722

                       Citicorp Mortgage Securities, Inc.
            (Issuer in respect of the REMIC Pass-Through Certificates
           Series 2005-1 through 2005-8 and CMALT Series 2005-A1 REMIC
                           Pass-Through Certificates)
                              (the "Certificates")
             ------------------------------------------------------
             (Exact name of Registrant as specified in its charter)


                       Delaware                     13-3408717
            -------------------------------     ----------------
            (State or other jurisdiction of     (I.R.S. Employer
            incorporation or organization)      Identification No.)

                1000 Technology Drive
                  O'Fallon, Missouri                  63368
            -------------------------------         ----------
            (Address of principal executive         (Zip Code)
             offices)

Registrant's telephone number, including area code: (636) 261-1313.
                                                    --------------

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

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

     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. [x]

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

     State the aggregate market value of the voting and non-voting common equity
held by non-affiliates computed by reference to the price at which the common
equity was last sold, or the average bid and asked priced of such common equity,
as of the last business day of the registrant's most recently completed second
fiscal quarter. NOT APPLICABLE

<PAGE>


                                     PART I

Item 1.  Business

         Omitted pursuant to an exemptive order dated July 10, 1987 (the
"Exemptive Order").

Item 2.  Properties

         The Annual Statement of Compliance for the Registrant's REMIC
Pass-Through Certificates Series 2005-1 through 2005-8 and CMALT Series 2005-A1
REMIC Pass-Through Certificates is included as Exhibit 99(a)(1) hereto.

Item 3.  Legal Proceedings.

         The Registrant knows of no material pending legal proceedings involving
either the trusts evidenced by the Certificates, the Registrant, the custodians
(as to each trust, CitiMortgage, Inc. ("CMI")), the subservicer (as to each
trust, CMI), or the trustee (as to each trust, U.S. Bank National Association)
with respect to each such trust, other than routine litigation incidental to the
business of the Registrant or each such custodian, subservicer or trustee.

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

         None.


<PAGE>


                                     PART II

Item 5.  Market for Registrant's Common Equity, Related Stockholder Matters and
         Issuer Purchases of Equity Securities.

         (a) To the best of Registrant's knowledge, there is no established
public trading market for the Certificates.

         (b) As of December 31, 2005, the number of holders of the Certificates
was as follows:

                                                                 Number of
                    Series                                        Holders
                    ------                                       ---------
                CMSI 2005-1                                          31
                CMSI 2005-2                                          18
                CMSI 2005-3                                          36
                CMSI 2005-4                                          16
                CMSI 2005-5                                          15
                CMSI 2005-6                                           9
                CMSI 2005-7                                          14
                CMSI 2005-8                                          12
                CMALT 2005-A1                                         5

         (c) Omitted pursuant to the Exemptive Order.

Item 6.  Selected Financial Data.

         Omitted pursuant to the Exemptive Order.

Item 7.  Management's Discussion and Analysis of Financial Condition and Results
         of Operation.

         Omitted pursuant to the Exemptive Order.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

         Omitted.

Item 8.  Financial Statements and Supplementary Data.

         In accordance with the Exemptive Order, the Annual Statement of
Compliance and the Annual Independent Accountant's Servicing Reports for the
Registrant's REMIC Pass-Through Certificates Series 2005-1 through 2005-8 and
CMALT Series 2005-A1 REMIC Pass-Through Certificates are included herein as
Exhibits 99(a)(1) and 99(a)(2), respectively.

Item 9.  Changes in and Disagreements with Accountants on Accounting and
         Financial Disclosure.

         None.

Item 9A. Controls and Procedures

         Not applicable.

Item 9B. Other Information

         None.

                                    PART III

Item 10. Directors and Executive Officers of the Registrant.

         Omitted pursuant to the Exemptive Order.

Item 11. Executive Compensation.

         Omitted pursuant to the Exemptive Order.



<PAGE>


Item 12. Security Ownership of Certain Beneficial Owners and Management.

         Omitted pursuant to the Exemptive Order.

Item 13. Certain Relationships and Related Transactions.

         Omitted pursuant to the Exemptive Order.


Item 14. Principal Accounting Fees and Services

         Not applicable.


                                     PART IV

Item 15. Exhibits, Financial Statement Schedules.

         (a)      Exhibits

          1       Certification pursuant to Section 302(a) of the Sarbanes-Oxley
                  Act. (Exhibit 31)

          2       The Registrant's Annual Statement of Compliance with respect
                  to the Certificates as to which CitiMortgage, Inc. ("CMI")
                  acts as subservicer. (Exhibit 99(a)(1))

          3       Annual Independent Auditors' Report with respect to the
                  Certificates as to which CMI acts as subservicer.(Exhibit
                  99(a)(2))


         (b)      Current Reports on Form 8-K

                  The Registrant filed the following Current Reports on Form 8-K
during the fiscal year ended December 31, 2005 relating to the REMIC Pass-
Through Certificates Series 2005-1 through 2005-8 and CMALT Series 2005-A1
REMIC Pass-Through Certificates:

<TABLE>
<CAPTION>

     Series                Date of Report
     ------                --------------
     <S>                   <C>
     CMSI 2005-1           February 9, 2005, February 24, 2005, March 25, 2005, April 25, 2005, May 25, 2005, June 27, 2005,
                           July 25, 2005, August 25, 2005, September 26, 2005, October 25, 2005, November 25, 2005, and
                           December 27, 2005

     CMSI 2005-2           March 8, 2005, March 24, 2005, March 28, 2005, April 25, 2005, May 25, 2005, June 27, 2005,
                           July 25, 2005, August 25, 2005, September 26, 2005, October 25, 2005, November 25, 2005, and
                           December 27, 2005

     CMSI 2005-3           April 11, 2005, April 28, 2005, May 25, 2005, June 27, 2005, July 25, 2005, August 25, 2005,
                           September 26, 2005, October 25, 2005, November 25, 2005, and December 27, 2005

     CMSI 2005-4           July 11, 2005, July 28, 2005, August 25, 2005, September 26, 2005 (two Reports), October 25, 2005,
                           November 25, 2005, and December 27, 2005

     CMSI 2005-5           August 4, 2005, August 25, 2005 (two Reports), August 26, 2005, September 26, 2005, October 25, 2005,
                           November 25, 2005, and December 27, 2005

     CMSI 2005-6           September 12, 2005, September 23, 2005, September 28, 2005, October 25, 2005, November 25, 2005, and
                           December 27, 2005

     CMSI 2005-7           September 28, 2005, October 6, 2005, October 24, 2005, October 27, 2005, November 25, 2005, and
                           December 27, 2005

     CMSI 2005-8           November 4, 2005, November 7, 2005, November 22, 2005, November 28, 2005, and December 27, 2005

     CMALT 2005-A1         July 18, 2005, July 27, 2005,August 25, 2005, September 26, 2005, October 25, 2005, November 25, 2005,
                           and December 27, 2005


</TABLE>

         The above Reports set forth under Item 2.01 thereof the
"Detailed Description of the Mortgage Pool and the Mortgaged Properties"
relating to the Series of Certificates to which such Reports relate.

         The above Reports set forth under Item 8.01 thereof (a) the
Computational Materials (as defined in the no-action letter dated May 20, 1994
issued by the Securities and Exchange Commission to Kidder Peabody Acceptance
Corporation-I, Kidder Peabody & Co. Incorporated and Kidder Structured Asset
Corporation) and/or Structural Term Sheets (as defined in the no-action letter
dated February 17, 1995 issued by the Securities and Exchange Commission to the
Public Securities Association) that are required to be filed pursuant to such
letters, (b) the "Collateral Term Sheets" relating to the Series of
Certificates to which such Reports relate, or (c) the monthly servicers reports
relating to the Series of Certificates to which such Reports relate.

     In the case of the above Reports relating to (a) Series 2005-2, such
Report sets forth under Item 9.01 thereof the Consent of KPMG LLP, independent
registered public accounting firm of Ambac Assurance Corporation and
subsidiaries, and (b) Series 2005-5, such Report sets forth under Item 9.01
thereof the Consent of PricewaterhouseCoopers LLP, independent registered public
accounting firm of Assured Guaranty Corp.

<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.


                                  CITICORP MORTGAGE SECURITIES, INC.
                                  (Registrant)


                                  By:/s/ Michael J. Tarpley
                                     ------------------------
                                  Name:  Michael J. Tarpley
                                  Title: Assistant Secretary


Dated:  March 28, 2006


      Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below on March 28, 2006 by the following persons on
behalf of the Registrant in the capacities indicated.

         Signature                                   Capacity
         ---------                                   --------

 /s/ Douglas R. Krueger                       President and a Director
 -------------------------                  (Principal Executive Officer)
    (Douglas R. Krueger)



                                                     Director
 -------------------------
    (Charles Wainhouse)


 /s/ Susan E. Chapman                                Director
 -------------------------
    (Susan E. Chapman)


 /s/ Paul Ince                         Senior Vice President, Chief  Financial
 -------------------------               Officer  (Principal Financial Officer
    (Paul Ince)                            and Principal Accounting Officer)


<PAGE>



                                  EXHIBIT INDEX


Exhibit No.

31                Certification pursuant to Section 302(a) of the Sarbanes-Oxley
                  Act.

99(a)(1)          The Registrant's Annual Statement of Compliance with respect
                  to the Certificates as to which CMI acts as subservicer.

99(a)(2)          Annual Independent Auditors' Report with respect to the
                  Certificates as to which CMI acts as subservicer.