My disability converted to retirement in December 2020. Can I payback or suspend social security now to get a higher benefit later?

Hi. You can voluntarily suspend your retirement benefits in order to earn delayed retirement credits (DRC), but you can't do so retroactively. The earliest that you can suspend your benefits is effective with the month after the month you request the voluntary suspension. So, for example, if you contacted Social Security today (i.e. May 5 2021), the earliest month that you could choose to suspend your benefits would be June 2021.

Best, Jerry