After completing the Form 1099-R there is a following screen which asks directly Was (Name) Employed as a Public Safety Officer?
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If you bypassed this screen then return to the Form 1099-R section to edit your 1099-R. Continue with the section until you are on the screen to answer the PSO question. Then continue with the section until it completes.
Enter 1099-r in the Search box located in the upper right of the program screen. Click on Jump to 1099-R