On the same screen for selecting the type of Form 1099-R that is being reported are selections for indicating who the form belongs to when filing a joint tax return.  See screenshot

To enter, edit or delete a form 1099-R -

• Click on Federal Taxes (Personal using Home and Business)
• Click on Wages and Income (Personal Income using Home and Business)
• Click on I'll choose what I work on (if shown)
• Scroll down to Retirement Plans and Social Security
• On IRA, 401(k), Pension Plan Withdrawals (1099-R), click the start or update button

Or enter 1099-r in the Search box located in the upper right of the program screen.  Click on Jump to 1099-R