Yes. The SS or FICA tax (they call it a "contribution" but try telling IRS you can't afford to make a contribution right now!) applies to all earned income in covered employment.
But if the earnings in a post-retirement year are higher than one of the year's earnings used to calculate the original benefit, SSA will re-calculate the benefit amount and any increase will be paid for years after the latest higher earnings year.
You can expedite that by bringing your w2 to the SSA office as soon as you get it and ask for a manual recomputation. They will do it automatically anyway, but it could be quite a while.
