I had a one time $80,000 capital gain in 2015. Will this affect my Social Security or Medicare for 2016?

[Hal_Al · Accepted solution]

It will not affect how much social security you are paid. That rule only applies to earned income, not investment income. It is not enough to affect your medicare premium, either.

But, it is added to your adjusted gross income (AGI) to determine how much of you social security benefits are taxable. If you were not already subject to 85% of your SS (the maximum) being taxable, you will be in 2015.