Retirement tax questions
The best way to enter Box 15 if there is no state identification number listed is to enter the Federal identification number of the payer. If there is no additional state or local information on the 1099R leaving the rest of the fields blank should be fine. Just enter the same number in box 15 that shows in the Payers TIN right above your name in most cases on the 1099R.
The highlighted field below is where you would enter the number:
