That is probably a CSA 1099-R from OPM.
OPM violates the 1099-R rules by writing "helpful" information in the box rather than just the value or code like they are supposed to. OPM has done that for years and it causes more confusion than help. They put UNKNOWN in box 2a when it should be blank, and put "7 NONDISABILITY" in box 7 when is should only be "7".
Enter a 1099-R here:
Federal Taxes,
Wages & Income
I’ll choose what I work on (if that screen comes up),
Retirement Plans & Social Security,
IRA, 401(k), Pension Plan Withdrawals (1099-R).
OR Use the "Tools" menu (if online version under My Account) and then "Search Topics" for "1099-R" which will take you to the same place.
Be sure to choose which spouse the 1099-R is for if this is a joint tax return.
Be sure to pick the correct 1099-R type: Standard 1099-R, CSA-1099-R, CSF-1099-R, RRB-1099-R.
[NOTE: When you get to the "Your 1099-R Entries" screen where you can add another 1099-R, use "continue" to keep going as there are additional interview questions after that screen in most cases. You can always return as shown above.]