This year is a little bit confusing. On my OPM Fed Retirement Block 1 has my gross income but block 2 has UNKNOWN due to block 5 having my ROTH contribution or insurance premiums paid in. It's Insurance. It not clear how much is paid in although you have a formula that calculates it. To get thru my return I just put in my Gross income so I could figure my taxes. Every year this area its confusing. Maybe you could let your calculator put up a note as to what I should actually put in. Would be helpful.