I have most of my taxable and non-taxable assets in stocks and real estate and REITs elsewhere, but I have about $120K in TIAA-CREF from jobs I left years ago. I wasn't paying much attention to it (bad behavior, I know), but I recently moved most of the equities & bond funds in that account to the TIAA Traditional, which, for the vintage I have, is paying a minimum of 3.49% per year. This is a very conservative investment, but I felt comfortable that it diversified me into something very safe. I'd rather have this than a CD.
I have a friend who started contributing to TIAA Traditional in the 1980s. His vintage is paying 7%. I wish I had that!
I don't know if what I did was the wisest move (comments welcome), but you might want to look into your options for safe diversification with TIAA.