Retirement tax questions

Are you sure that there should be a number in box 20 of the Social Security benefit worksheet?

Entering  a SSA-1099 doesn't always mean you will have a taxable amount that will show in box 20. If you check line 6 of your 1040, 6a will show the amount of Social Security income and 6b will show the taxable amount. 

Since you are looking at the Social Security benefit worksheet, do you see any amounts on line 1? Whether it is taxable or not, the amount you entered should show on line 1. 

If you have contributed to a traditional IRA, or if you received a lump sum distribution, the taxable amount may not show on box 20. See below, where the taxable amount was calculated on a different worksheet.