The letter from Medicare arrives about a year after the funeral. The income is the same. The premium is not.
Nothing was missed. IRMAA thresholds for a single filer sit at half the thresholds for a couple, so income that was under the line last year can sit over it now.
Every figure here is for 2026, checked against CMS and Form SSA-44. Medicare premiums reset annually. Educational only, not tax, legal, or financial advice.
Why does the premium rise when your income did not?
IRMAA, the Income-Related Monthly Adjustment Amount, is a surcharge Medicare adds to the standard Part B premium once modified adjusted gross income (MAGI) passes a set level, per the Centers for Medicare & Medicaid Services. It applies to Part D drug coverage too.
8%
Roughly the share of people with Medicare Part B who pay an IRMAA surcharge.
CMS
It runs on two tables, one for single filers and one for joint. A couple has twice the room before it starts. A widow or widower filing single has half that room, on income that rarely fell by half.
What are the 2026 Medicare IRMAA brackets?
$202.90
The 2026 standard monthly Part B premium, up from $185.00 in 2025.
CMS, Nov 14, 2025
$283
The 2026 annual Part B deductible.
CMS, Nov 14, 2025
Above the standard premium, six income tiers set the surcharge.
| MAGI, single filer | MAGI, joint filer | IRMAA | Total Part B premium |
|---|---|---|---|
| $109,000 or less | $218,000 or less | $0.00 | $202.90 |
| $109,000.01 to $137,000 | $218,000.01 to $274,000 | $81.20 | $284.10 |
| $137,000.01 to $171,000 | $274,000.01 to $342,000 | $202.90 | $405.80 |
| $171,000.01 to $205,000 | $342,000.01 to $410,000 | $324.60 | $527.50 |
| $205,000.01 to under $500,000 | $410,000.01 to under $750,000 | $446.30 | $649.20 |
| $500,000 or more | $750,000 or more | $487.00 | $689.90 |
Every single-filer threshold is exactly half its joint counterpart through the $205,000 tier. It breaks only at the top: $500,000 single against $750,000 joint, 1.5 times rather than double. The compression is worst at the highest tier.
What does that cost in real money?
Take $150,000 of MAGI in 2026. Filed single, it lands in the third bracket, above $137,000: IRMAA of $202.90, total premium $405.80 a month.
The identical $150,000 filed jointly sits under the $218,000 threshold. No surcharge, $202.90.
$2,434.80
Extra Part B premium in a year, on identical income, from filing status alone.
Worked from the 2026 CMS brackets
Part D adds its own IRMAA on top. Which raises the obvious question.
Can Form SSA-44 undo it?
Form SSA-44 asks Social Security to recalculate IRMAA from a more recent year's income instead of the two-year-old return Medicare defaults to. Death of a spouse is one of the eight life-changing events listed on it, alongside marriage, divorce, and work stoppage. The catch sits in the form's opening line.
"If you had a major life-changing event and your income has gone down, you may use this form to request a reduction in your income-related monthly adjustment amount."
The gate is the income drop. A change in filing status "might also" reduce the adjustment, the instructions say, on top of a real income reduction rather than instead of one.
So losing a spouse qualifies a person to file. A survivor whose income held steady, pushed up a bracket only because the single thresholds are half the joint ones, does not meet that test on its own.
That is not a reason to skip it. Most survivors do see income fall, from a lost pension, a paycheck, or one of two Social Security checks, and the form is built for exactly that. Both mistakes cost money: filing on the wrong basis wastes the paperwork, not filing after a real drop means overpaying Medicare for a year.
Why does the bill arrive two years late?
Medicare sets each year's IRMAA from a tax return two years old. Form SSA-44 states it directly: 2026 premiums come off the return filed for tax year 2024, or 2023 if 2024 is not available yet.
2 years
Between the tax return that sets the premium and the year it is charged.
Form SSA-44
A couple's final joint return can carry a one-time event, a Roth conversion or a large capital gain, taxed at joint rates against a joint threshold. Two years on, that return sets the survivor's premium against a threshold half as wide, in a year the household has already adjusted to one income. Our retirement tax planning page covers how conversion timing interacts with brackets.
What else changes at the same time?
IRMAA is one line in a larger shift. Filing status changes, the standard deduction is cut roughly in half, and Social Security decisions made years earlier keep playing out. Our page on retirement planning after losing a spouse covers the filing-status cliff and the inherited IRA rules; the Social Security claiming age page covers how a survivor benefit and a person's own benefit can be sequenced.
None of it argues for rushing. It argues for knowing which numbers carry a two-year lookback, so a choice made in the last joint-filing year does not resurface as a Medicare bill.
PlanVault connects you with a trusted, licensed financial advisor, at no cost to you. No guide to download, no information to trade first, just a straight, no-obligation review of where your Medicare and tax picture stands.