1099-R, block 7

I receive a Federal annuity from the Office of Personnel Management (OPM).  Turbo Tax asks for the codes in Blocks 7a and 7b and won't let me continue without entering them.  My 1099-R from OPM doesn't have these blocks.  It has Block 7 which shows "7 - NONDISABILITY."  The Turbo Tax drop down has a code 7, but it is not described as "NONDISABILITY."  When I select "7" from the drop down, it asks questions that make it sound like this is money distributed from an IRA, 401(k).  I am confused.  Please help.  Thank you.