My benefits were decreased in 2020 as a result of a 2018…

I'm sorry this happened. Yes there is a process.

IRMAA is determined by income from your income tax returns two years prior. This means that for your 2022 Medicare premiums, your 2020 income tax return is used. This amount is recalculated annually. The IRMAA surcharge will be added to your 2022 premiums if your 2020 income was over $91,000 (or $182,000 if you’re married)

You can apply to Social Security to reduce your Medicare premium in light of changed financial circumstances.

Social Security uses tax information from the year before last — typically the most recent data it has from the IRS — to determine if you are a “higher-income beneficiary.” If so, you will be charged more than the “standard,” or base, premium for Medicare Part B (health insurance) and, if you have it, Part D (prescription drug coverage).

But a lot can happen in the intervening year, so Social Security provides a way to review your premium on the basis of a “life-changing event” that significantly affected your income, such as:

-A marriage, a divorce or the death of a spouse.

-Stopping or reducing work.

-Loss of an income-producing property for reasons beyond your control.

-A major change in or termination of your employer’s pension plan.

-A financial settlement with an employer (due to a company reorganization or bankruptcy, for example) that inflated your income one year but does not reflect your current financial situation.

To request a reduction of your Medicare premium, call(###) ###-####to schedule an appointment at your local Social Security office or fill out form SSA-44 and submit it to the office by mail or in person. You’ll need to provide a copy of the more recent tax return and evidence of the life-changing event (the SSA-44 includes a checklist of acceptable documentation).

I see, so you want them to make a retroactive adjustment for something that has already happened?!

I think its a perfectly reasonable request, especially since the IRS cooperated. You should open up a case with your local SSA office.