It doesn't matter from which account you withdraw your RMD from, just so the total required RMD of all accounts is withdrawn. You could combine all of your RMD's and take it from one account or you could take the required RMD from each account. Combining your RMD's from TIAA and Fidelity IRA is fine, jut as long as you also took the required RMD from your Fidelity 403(B) account, which it seems you did. Just enter the 2 1099-r's as retirement income.
