I spoke with a representative from Tiaa 1st to be sure. Then I tried transfering about 1,000 back and forth to make sure there were no issues.
I know the accounts that are restrictive on movement pay a higher rate, and older vintages were paying more too.
You can find more information here
http://www.profsadvisor.com/search?updated-max=2014-08-14T15:09:00-07:00&max-results=7This is from the above website
"Restrictions
For those of you with TIAA Traditional within a Group Retirement Annuity (GRA), Retirement Annuity (RA), or a Retirement Choice (RC) contract, there are restrictions that prevent you from moving your accumulation out in a lump sum. Due to these restrictions TIAA Traditional vintages within a GRA, RA, and RC contracts pay a higher interest rate than other accounts.
However, investors with a Supplemental Retirement Annuity (SRA), Group Supplemental Retirement Annuity (GSRA), or Individual Retirement Account (IRA or Roth), are able to transfer money into and out of TIAA Traditional in a lump sum. If you transfer money out of TIAA Traditional in a lump sum and then move it back within 120 days, you receive the same vintages up to the amount you had originally invested. If you transfer money out of TIAA Traditional and wait over 120 days to transfer an accumulation back, you will receive the new vintage rate. "