My wife elected to receive Soc Sec benefits at age 68 commencing in 2016 and was also paid a lump-sum in 2016 for 2015, which was included in her 2016 SSA-1099 box 5. After entering this info in Turbo Tax, I was then required to enter our 2015 AGI, tax-exempt interest, and taxable SS--which then suddenly triggered a big jump in FIT due. When I undid these last 3 entries as a test, the Federal Review spit out an error, and I was forced to re-enter these 3 entries. What is the linkage and logic between her 2015 lump-sum benefit and my 2015 Soc Sec benefits on which I've already paid taxes for 2015??
... View more