Yes. It must be accounted for in 1 of 2 ways.
- Declare the income on your 2016 tax return, and have the entire amount taxed according to your 2016 income tax return. Just enter the 1099-SSA as you see it, ignoring that some of the income relates to a prior year.
- Elect the lump sum method. By doing this, you are taxed on the 2014 and 2015 amounts as if the income was received and reported on the prior year tax returns. To choose this, you will need your 2014 and 2015 tax returns, as you will need to reference the numbers on them.
Click on the link below for detailed instruction on reporting a lump sum:
https://ttlc.intuit.com/questions/3440981-my-ssa-1099-shows-lump-sum-for-2014-and-2015-tt-only-lets-...
