amending return from MFS to MFJ to reduce IRMAA Medicare surcharge

My wife and I filed separate returns in 2020 (MFS), because her situation was very complex (with some inheritance and such) and she wanted to have a CPA do it, and it was also one of these unusual occasions when MFS results in a lower tax bill (I had a bunch of capital-gains being taxed at 0%). I knew she would probably get hit by IRMAA (increased Medicare premiums for taxpayers with higher AGI), but until she just received her premium notice for 2022, we did not realize that IRMAA is different (with fewer and lower thresholds and higher surcharges) for MFS than for single filers. It's a whopper It seems it'd be beneficial for us to file and amended return, changing our filing status from MFS to MFJ. I gather this is legal and reasonable. My questions: If we do this, thereby qualifying for a smaller (or perhaps even zero) IRMAA surcharge, how will Medicare adjust our premium amounts ? How difficult is it ? I gather we have to present the amended return to Medicare, along with acknowledgement of its receipt by the IRS. Given that 2022 is barely over a month away, one imagines the reduced IRMAA won't be in effect until well into 2022 ? Will Medicare refund the extra premiums paid before the change occurs ? If we file this amended return, must we also file an amended state return, since you're generally required to use the same filing status for federal and state ? If it makes very little difference in the state tax bottom-line, are we likely to be able to get away with just skipping the amended state return ?

1 Answer 1

If you amended your tax return, and it changes the income we count to determine the income-related monthly adjustment amounts, let us know. Social Security needs to see a copy of the amended tax return you filed and your acknowledgment receipt from IRS.

I'm not quite sure I understand. The amended MFJ return will show the same income as our original MFS returns combined. But the IRMAA rules mean that the MFJ AGI makes us each pay 1.4X the standard amount ($170 for 2022), whereas under MFS rules I pay 1X and she pays 3.2X. Thus we save a total of 1.4X which amounts to about $2800 over the course of 2022.

Seems like if you want them to do anything, send SS the amended return and acknowledgement receipt. Otherwise they'll carry on with the original calculations.