The program uses your birthday as it is entered in the Personal Info section of the program. You can verify that your date of birth is entered correctly by clicking on Personal Info in the TurboTax menu, and then clicking Edit beside your name.
**Mark the post that answers your question by clicking on "Mark as Best Answer"
TurboTax goes almost entirely by the code in box 7 of the Form 1099-R, except in the year that you reached age 59½ as indicated by the date of birth that you entered in which case TurboTax explicitly asks if the distribution was received before or after you reached age 59½ (but only uses your answer to determine what to do next and does not record the answer; if you revisit this question you must re-answer the question). If box 7 does not include code 1 or code J, the distribution is not subject to penalty.