Retired Couple With $1.9 Million Faces $4,800 IRMAA Surprise After Stock Sale

A retired couple sitting on a $1.9 million nest egg opens a letter from Social Security and learns their 2026 Medicare premiums are going up by roughly $4,800 for the year. The trigger happened two years ago when they sold appreciated tech stock to pay for a kitchen renovation and booked a big long-term capital gain. They were unaware that Medicare looks backward two tax years when it sets premiums.

In this example, a 65-year-old couple enrolled in Medicare this year. Two years ago, they realized $180,000 in long-term capital gains to fund that remodel. That one-time event pushed their modified adjusted gross income (MAGI) for that tax year to roughly $310,000. Because Medicare uses a two-year MAGI lookback, that single tax return now drives their 2026 Part B and Part D premiums into a higher Income-Related Monthly Adjustment Amount (IRMAA) tier, costing them about $4,800 in extra premiums across both spouses for the year.

Higher IRMAA tiers can be triggered by a Roth conversion, a business sale, an inherited IRA distribution, or a one-off brokerage liquidation. The common thread is that the household never modeled the downstream Medicare cost before pulling the trigger.

The surcharge was completely avoidable with planning and is completely unavoidable now. IRMAA works as a cliff: cross a tier boundary by one dollar and the full surcharge applies for twelve months.

The 2026 standard Part B premium is $202.90 per month with an annual deductible of $283. At MAGI between $274,000 and $342,000, each spouse pays an additional $202.90 per month on top of the base Part B premium, for a total of $405.80 monthly. Part D adds another $37.50 per month per spouse in the same tier. Multiply across both spouses and 12 months and you arrive at the surcharge the couple is now stuck with.

Their MAGI in the following year returned to normal, so the IRMAA hit is a single-year event. There is unfortunately no appeal for “I sold stock to remodel my kitchen.”

Three Moves That Could Change the Outcome

For anyone still in the planning window, these are the levers that work. For the couple in the scenario, only one applies retroactively.

1. Bunch capital gains into pre-Medicare years. The IRMAA lookback window opens at age 63 for someone enrolling at 65. Large discretionary realizations, home renovation funding, gifting to adult children, and paying off a mortgage are far cheaper if completed before that window. Selling appreciated stock at 60 or 61 costs you the long-term capital gains tax and nothing else. Selling the same stock at 63 or 64 tacks on a Medicare premium surcharge two years later.
2. File Form SSA-44 if a Life-Changing Event applies. SSA-44 lets you ask Social Security to use a more recent year’s income instead of the two-year lookback when a qualifying event has lowered your income. Retirement itself qualifies. Marriage, divorce, death of a spouse, loss of pension, and reduction in work hours also qualify. A discretionary stock sale does not. If the lookback year was also the year you retired, file the form.
3. Plan realizations around the lookback calendar, not the calendar year. Before any large taxable event after age 62, run the MAGI math against the joint-filer IRMAA tiers. Sometimes splitting a sale across two tax years keeps you under a cliff. Sometimes accelerating into the current year is better. The decision depends on where you sit relative to the nearest tier boundary, which is published each fall by CMS.

If you are between 62 and 65 and have appreciated taxable assets, pull your most recent tax return and project MAGI for the current year and next year. Compare both to the 2026 joint-filer tier breaks at $218,000, $274,000, $342,000, $410,000, and $750,000. If a planned sale would push you across a cliff, ask whether the same goal can be funded from cash, a HELOC, or a partial sale that stays under the line.

If you are already inside the lookback window and the high-income year coincided with retirement, marriage, divorce, or a spouse’s death, file SSA-44 with documentation. It is the only retroactive lever that exists.

Don’t think of capital gains tax as the full cost of a stock sale. For anyone within two years of Medicare enrollment, the IRMAA shadow is real money, and it shows up on a delay long after the brokerage statement is forgotten.