For TIAA's first twenty years, its corporate stock was owned by Carnegie Corporation of New York, which provided TIAA's $500,000 endowment grant. In 1938, Carnegie Corporation turned over ownership of TIAA to the new company, named Trustees of T.I.A.A. Stock. In 1989, Trustees of T.I.A.A. Stock was renamed TIAA Board of Overseers.
The Overseers are responsible for defining the mission of TIAA, overseeing TIAA’s business strategies and performance in consultation with the CEO and management, reviewing policy issues affecting TIAA, overseeing matters that could threaten the general reputation of TIAA, electing the members of the TIAA Board of Trustees, filling vacancies by appointment, and approving amendments to TIAA's charter and bylaws.
The TIAA Board of Overseers normally consists of seven members — including the TIAA CEO and president — and each member serves a seven-year term. By charter, the seven members of the TIAA Board of Overseers are the same seven members of the CREF Board of Overseers.