Exhibit 99.906CERT

CERTIFICATION PURSUANT TO 18 U.S.C. 1350, AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Report of Mutual of America Investment Corporation (the “Investment Corp.”) on Form N-CSR for the semi-annual period ended June 30, 2014 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, John R. Greed, Chairman of the Board, President and Chief Executive Officer of the Investment Corp., certify that:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Investment Corp. for the period ended June 30, 2014.

Dated: September 4, 2014

 /s/ JOHN R. GREED

 John R. Greed

 Chairman of the Board,

 President and Chief Executive Officer of

 Mutual of America Investment Corporation

CERTIFICATION PURSUANT TO 18 U.S.C. 1350, AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Report of Mutual of America Investment Corporation (the “Investment Corp.”) on Form N-CSR for the semi-annual period ended June 30, 2014 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, George L. Medlin, Executive Vice President, Chief Financial Officer and Treasurer of the Investment Corporation, certify that:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Investment Corp. for the period ended June 30, 2014.

Dated: September 4, 2014

 /s/ GEORGE L. MEDLIN

 George L. Medlin

 Executive Vice President,

 Chief Financial Officer and Treasurer of

 Mutual of America Investment Corporation