I plan to retire next year. I will be 70 next August. I'm employed and collecting social security now.
My social security benefit has been going up each year because i'm replacing the top earning years now against my lower income years..
The question is: Would I increase my social security benefit by working until December of next year or is the benefits calculated on my income up to my birthday in August.

Hi,

Your 2020 earnings can be used in the calculation of your Social Security retirement benefit rate starting with your payment for the month of January 2021, however, your 2020 earnings will only raise your benefit rate if your 2020 earnings are higher than one of your previous 35 highest years of wage-indexed earnings (https://www.ssa.gov/pubs/EN-05-10070.pdf). Earnings on which you pay Social Security taxes can be used to calculate your benefit rate regardless of your age at the time you produce the earnings, so if you earn more by working until December next year that could potentially boost your benefit rate but only if your 2020 earnings are higher than one of your previous highest 35 years of wage-indexed earnings.

Best, Jerry