Medicare Part D

How Your Income Shapes Medicare Costs in 2026

Winchester, Virginia — As Medicare's Annual Enrollment Period runs through Dec. 7, many Winchester retirees are opening letters from Social Security and spotting an unfamiliar acronym: IRMAA. If your income crossed a certain line two years ago, it can quietly raise what you pay for Medicare Part B and Part D in 2026 — and catching it early is the difference between a smooth year and a frustrating one.

Here's a plain-language guide to how income affects your Medicare costs next year, what the thresholds look like, and how to avoid the most common mistakes.

What IRMAA actually is

IRMAA stands for the Income-Related Monthly Adjustment Amount. It's an extra charge added on top of the standard Part B premium and, separately, on top of your Part D drug plan premium. It's not a penalty for doing anything wrong — it's simply a higher premium tier for people whose income is above a set level.

Two important things to know up front:

• IRMAA is set by the Social Security Administration, not by your insurance company.
• It's based on your tax return from two years ago. So your 2026 Medicare premiums are based on the income you reported on your 2024 tax return.

The 2026 income thresholds

For 2026, IRMAA begins when your modified adjusted gross income (MAGI) is above $109,000 for a single filer or above $218,000 for a married couple filing jointly, according to CMS guidance on Medicare costs at medicare.gov.

If your income is at or below those numbers, you pay the standard Part B premium and only your plan's regular Part D premium — no surcharge.

If your income is above those numbers, you move into one of several higher tiers. The higher the tier, the larger the monthly add-on for both Part B and Part D. The top tier applies to single filers with income above roughly $500,000 and joint filers above roughly $750,000.

The exact dollar amount for each tier is published by CMS each fall. You can view the full chart on medicare.gov under "Costs."

How you'll find out you owe it

If IRMAA applies to you in 2026, Social Security will mail you a "predetermination" or "initial determination" notice, usually late in the year. The letter will tell you:

• Which tax year they used (normally 2024 for 2026 premiums),
• Your reported income,
• The extra amount you'll owe each month for Part B and Part D.

Part B IRMAA is deducted from your Social Security check, or billed if you're not yet drawing benefits. Part D IRMAA is billed separately by Medicare — not by your drug plan — even though your plan premium still goes to the insurer. That surprises a lot of people the first year.

Life changes that can lower your IRMAA

This is the part many folks in the Winchester area miss. If your income has dropped since 2024 because of a "life-changing event," you can ask Social Security to recalculate. Qualifying events include:

• Retirement or reduced work hours
• Death of a spouse
• Marriage or divorce
• Loss of pension income
• Loss of income-producing property (not from normal market swings)

You file Form SSA-44 with documentation. If approved, Social Security uses a more recent, lower income figure instead of your 2024 return. This is one of the most useful and least-known tools in Medicare, and it's worth acting on quickly if it applies to you.

You can also appeal an IRMAA determination if you believe the income data is wrong — for example, if you amended your tax return.

Mistakes to avoid this fall

A few pitfalls we see every enrollment season:

• Ignoring the letter. Even if you disagree, don't toss it. You have a limited window to request a reconsideration.
• Assuming your plan can waive it. No insurance company can remove or reduce IRMAA. It's a federal calculation.
• Forgetting the two-year lookback. A big one-time income event in 2024 — selling a home, a Roth conversion, cashing out stock — can push your 2026 premiums higher even if your income is normal now.
• Overlooking Part D IRMAA if you don't have a drug plan. If you owe Part D IRMAA but aren't enrolled in a Part D plan, you still owe it as long as you have creditable drug coverage through another source that triggers the rule. Check your notice carefully.

How this fits into your 2026 plan choices

Winchester is in Winchester City, where Medicare beneficiaries choose between Original Medicare (with or without a standalone Part D drug plan and a Medigap policy) and Medicare Advantage plans that combine coverage. IRMAA applies the same way regardless of which path you pick — it's tied to your income, not your plan.

A few other 2026 program-level facts worth knowing as you compare coverage during Annual Enrollment (Oct. 15 – Dec. 7):

• Part D has a new $2,100 out-of-pocket cap on covered drugs.
• The Part D deductible can be no higher than $615.
• The old "donut hole" is gone; Part D now has three phases.
• The Medicare Prescription Payment Plan lets you spread drug costs across the year in monthly installments at no added cost.

If you miss Annual Enrollment, people already in a Medicare Advantage plan get a second window — the Medicare Advantage Open Enrollment Period — from Jan. 1 to March 31 to make one change.