Exhibit 31.2

                      CERTIFICATION PURSUANT TO SECTION 302
                        OF THE SARBANES-OXLEY ACT OF 2002

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I, John R. Greed, Executive Vice President, Chief Financial Officer and
Treasurer of Mutual of America Investment Corporation, certify that:

      1. I have reviewed this report on Form N-CSR of Mutual of America
Investment Corporation;

      2. Based on my knowledge, this report 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 with respect to the period covered by this report; and

      3. Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material respects the
financial condition, results of operations, changes in net assets, and cash
flows (if the financial statements are required to include a statement of cash
flows) of the registrant as of, and for, the periods presented in this report.

      4. The registrant's other certifying officer and I are responsible for
establishing and maintaining disclosure controls and procedures (as defined in
Rule 30a-2(c) under the Investment Company Act of 1940) for the registrant and
have:

            a) designed such disclosure controls and procedures to ensure that
      material information relating to the registrant, including its
      consolidated subsidiaries, is made known to us by others within those
      entities, particularly during the period in which this report is being
      prepared;

            b) evaluated the effectiveness of the registrant's controls and
      procedures as of a date within 90 days prior to the filing date of this
      report (the "Evaluation Date"); and

            c) presented in this report our conclusions about the effectiveness
      of the disclosure controls and procedures based on our evaluation as of
      the Evaluation Date;

      5. The registrant's other certifying officer and I have disclosed, based
on our most recent evaluation, to the registrant's auditors and the audit
committee of the registrant's board of directors (or persons performing the
equivalent functions):

            a) all significant deficiencies in the design or operation of
      internal controls which could adversely affect the registrant's ability to
      record, process, summarize, and report financial data and have identified
      for the registrant's auditors any material weaknesses in internal
      controls; and

            b) any fraud, whether or not material, that involves management or
      other employees who have a significant role in the registrant's internal
      controls; and

      6. The registrant's other certifying officer and I have indicated in this
report whether or not there were significant changes in internal controls or in
other factors that could significantly affect internal controls subsequent to
the date of our most recent evaluation, including any corrective actions with
regard to significant deficiencies and material weaknesses.

Date: August 30, 2004

                                    /s/ JOHN R. GREED
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                                    John R. Greed,
                                    Executive Vice President,
                                    Chief Financial Officer and Treasurer of
                                    Mutual of America Investment Corporation