What eventually happens when my Medicare premium is MORE than my Social Security benefit?

Most of my working life was not subject to Social Security taxes (yes, this can happen legitimately in the US), therefore my Social Security benefit is very modest.

My Medicare premium is withheld from my SS benefits, and in 2020 my monthly SS benefit was only a few dollars per month more than my monthly Medicare premium. Moreover, because they recalculated my IRMAA for 2019 early in 2020, I owed them $$ from 2019 and they stopped sending me SS checks early in 2020. OK, no problem. But at a few dollars per month, it would have taken them about 10 years to recoup what they overpaid me in 2019, but they didn’t seem to have figured this out. Now it is 2021, and my Medicare premium is more than my SS benefit.

I am curious: What will happen eventually? The amount I owe will become larger each month. Is Medicare eventually going to send me a bill? Will they start sending me monthly (or quarterly or yearly) bills? I don’t want to ask them, because why stir them up, particularly now, when nobody needs more to do.