Medicare Part D

Denver Medicare: Income Thresholds That Trigger IRMAA

DENVER — As Medicare's Annual Enrollment Period runs through Dec. 7, higher-income retirees in the Mile High City are getting a closer look at a line item that surprises many first-time enrollees: the Income-Related Monthly Adjustment Amount, or IRMAA. If your 2024 tax return showed more than $109,000 in income as a single filer (or $218,000 filing jointly), your 2026 Medicare Part B and Part D premiums will include a surcharge on top of the standard amounts.

Here's what Denver-area readers should understand before the enrollment window closes.

What IRMAA is — and why it exists

IRMAA is not a penalty. It's an income-adjusted premium that higher earners pay for Part B (doctor visits and outpatient care) and Part D (prescription drugs). Most people pay only the standard Part B premium and whatever their Part D plan charges. But if your modified adjusted gross income (MAGI) crosses certain thresholds, Social Security adds a surcharge to both.

Medicare uses your tax return from two years earlier to set the current year's premium. That means your 2027 premiums will be based on the income you reported on your 2025 tax return.

The 2027 income thresholds

For 2026, IRMAA kicks in above these MAGI levels:

• Single filer: more than $109,000
• Married filing jointly: more than $218,000
• Married filing separately: a much lower threshold applies, so check with Medicare directly

There are five surcharge tiers. The higher your income, the higher the add-on for both Part B and Part D. The top tier applies to single filers with MAGI at or above $500,000 and joint filers at or above $750,000.

Exact dollar amounts for each tier are published by CMS at Medicare.gov. The 2027 figures are expected later this fall, so it's worth confirming them there rather than relying on older charts.

How the Part D surcharge works alongside 2027 drug changes

The Part D IRMAA is added to whatever monthly premium your drug plan charges — Medicare collects it separately, usually from your Social Security check.

That surcharge sits on top of some meaningful 2027 program changes worth knowing:

• The Part D out-of-pocket cap is $2,100 in 2026. Once your covered drug costs hit that limit, you pay $0 for covered drugs the rest of the year.
• The maximum Part D deductible is $615.
• The old "donut hole" coverage gap is gone. Part D now has three simpler phases.
• The Medicare Prescription Payment Plan lets you spread your drug costs into level monthly payments instead of paying big amounts at the pharmacy counter.

If you take expensive medications, these changes may matter more to your annual budget than the IRMAA surcharge itself.

How to decide what to do about it

If you're a Denver retiree looking at an IRMAA bill for the first time, here are the practical steps:

1. Confirm the income Medicare is using. Social Security sends a letter each fall explaining which year's tax return determined your surcharge and what tier you're in. Read it carefully.

2. Check whether you had a life-changing event. If your income has dropped since 2024 because of retirement, a spouse's death, divorce, or loss of a pension or work income, you can ask Social Security to recalculate. The form is SSA-44, "Medicare Income-Related Monthly Adjustment Amount – Life-Changing Event." This is one of the most under-used tools in Medicare.

3. Look at the full picture before switching plans. During AEP (through Dec. 7) and again during Medicare Advantage Open Enrollment (Jan. 1 – Mar. 31), you can change coverage. But IRMAA follows you — it's tied to your income, not your plan. Switching plans doesn't remove the surcharge.

4. Think about tax planning for future years. Roth conversions, large capital gains, or one-time IRA withdrawals in a given year can push you over a threshold two years later. A conversation with a tax professional before year-end can prevent surprises.

Where Denver residents can get local help

Denver is in Denver County, where dozens of Medicare Advantage and stand-alone Part D plans are offered — but IRMAA is a federal calculation and doesn't depend on which plan you pick.

For personalized help, Coloradans can contact the Colorado State Health Insurance Assistance Program (SHIP), run through the Colorado Division of Insurance. SHIP counselors are trained volunteers who don't sell plans and don't earn commissions. They can walk through your Social Security letter and explain your appeal options.