I have received a check for monies called "investment in contract monies" which could not be rolled over. From TIAA Cref. What exactly are IVC monies, and am I responsible for taxes on this money?

Maybe. A phone call to TIAA-CREF should get you an answer as to whether it is dividends or interest (which ARE taxable) or a return of principal (which is NOT taxable) or a capital gain (which is taxable, but at a different rate than dividends/interest).