MUTUAL OF AMERICA INVESTMENT CORPORATION

                             ARTICLES SUPPLEMENTARY
                                     TO THE
                           ARTICLES OF INCORPORATION

      Mutual of America  Investment  Corporation,  a Maryland  corporation  (the
Corporation),  with its principal office c/o The Corporation Trust Incorporated,
300 East Lombard  Street,  Baltimore,  Maryland 21202,  hereby  certifies to the
State Department of Assessments and Taxation of Maryland that:

      FIRST: The total number of shares of capital stock of all classes that the
Corporation  has  authority  to issue  is three  billion  five  hundred  million
(3,500,000,000)  shares  of common  stock,  par value  $.01 per  share,  with an
aggregate par value of thirty five million dollars ($35,000,000).

      SECOND:  That the  classes  of shares  currently  designated  as the Asset
Allocation  Growth Fund,  Asset  Allocation  Growth and Income  Fund,  and Asset
Allocation  Income Fund are redesignated as the Aggressive  Allocation Fund, the
Moderate  Allocation Fund and the Conservative  Allocation  Fund,  respectively,
which shares shall have the relative  preferences,  conversion and other rights,
voting powers,  restrictions,  limitations as to dividends,  qualifications  and
terms and conditions of redemption as previously allocated to the Funds.


      IN WITNESS WHEREOF, the Senior Executive Vice President of the Corporation
has signed these Articles  Supplementary  in the  Corporation's  name and on its
behalf and  acknowledges  that these Articles  Supplementary  are the act of the
Corporation,  and  states  that to the best of his  knowledge,  information  and
belief all matters and facts set forth therein relating to the authorization and
approval of the Articles  Supplementary  are true in all  material  respects and
that this statement is made under the penalties of perjury.

Dated: April 17, 2003

                                            MUTUAL OF AMERICA
                                            INVESTMENT CORPORATION


Attest:
                                            -----------------------------------
                                            Manfred Altstadt, Senior Executive
                                            Vice President and Chief Financial
                                            Officer


--------------------------------
 Deborah S. Becker, Secretary


(seal)