Medicare Part D

How IRMAA shapes Medicare Part B and D in Kapolei

KAPOLEI, Hawaii — As Medicare's Annual Enrollment Period runs through Dec. 7, higher-earning retirees on the Leeward coast are getting a fresh look at how their tax returns can shape what they pay for Part B and Part D next year. The rule is called IRMAA — the Income-Related Monthly Adjustment Amount — and for 2026 it kicks in once a single filer's income tops $109,000. If that sounds like you, the number on your 2024 tax return matters more than you might think.

What IRMAA is, in plain terms

Most people on Medicare pay the standard Part B premium and whatever premium their Part D drug plan charges. But if your income is above a certain level, Social Security adds an extra amount on top of both. That extra is IRMAA. It is not a penalty — it is an income adjustment written into Medicare law.

The surcharge is billed monthly. For Part B, it is added to your Part B premium (usually pulled from your Social Security check). For Part D, it is billed separately by Medicare, even though your drug plan premium itself still goes to your plan.

The income thresholds for 2026

For 2026, IRMAA begins once your modified adjusted gross income (MAGI) crosses these lines:

• Single filer: more than $109,000
• Married filing jointly: more than $218,000
• Married filing separately: a lower, separate threshold applies

There are several tiers above those starting points. The higher your income, the larger the surcharge on both Part B and Part D. Medicare.gov posts the full tier chart each year, and it is worth checking directly rather than relying on last year's numbers.

Why your 2024 tax return matters now

Here is the part that surprises people in Kapolei and across Honolulu County: Medicare does not use your current income. It uses the most recent tax return the IRS has shared with Social Security — which for 2027 premiums will generally be your 2025 return.

That means a one-time bump in 2025 income — selling a home, cashing out stock, taking a large IRA withdrawal — can push you into an IRMAA tier in 2027 even if your income has since dropped back down.

When you can ask for a review

Life changes. Medicare knows that. If you've had a "life-changing event," you can ask Social Security to use more recent income instead. Qualifying events include:

• Retirement or reduced work hours
• Marriage, divorce, or the death of a spouse
• Loss of a pension or an income-producing property
• A settlement from a former employer

The form to request this review is SSA-44, available at ssa.gov. You'll need documentation of the event and your expected income.

What this looks like locally

Kapolei is in Honolulu County, where Medicare beneficiaries can compare available Part D and Medicare Advantage options during the Annual Enrollment Period (Oct. 15 – Dec. 7). IRMAA applies the same way in Hawaii as it does anywhere else — it is a federal calculation, not a state one — but Hawaii's higher cost of living means retirees here often have pension, rental, or investment income that lands them near the thresholds without realizing it.

A few other program numbers worth knowing

While you are reviewing your income picture, keep these program-level figures in mind for 2026:

• Part D out-of-pocket cap: $2,100 for the year
• Part D maximum deductible: $615
• The coverage gap (donut hole) is gone as of 2025 — Part D now has three phases
• The Medicare Prescription Payment Plan lets you spread drug costs across the year in monthly payments, at no extra charge

Where to get personalized help

IRMAA questions are personal because they depend on your tax return. For help specific to your situation:

• Visit medicare.gov for current premium and IRMAA charts
• Call 1-800-MEDICARE (1-800-633-4227), TTY 1-877-486-2048
• Contact Hawaii SHIP (the State Health Insurance Assistance Program) for free, unbiased counseling
• Call or visit Social Security at ssa.gov for IRMAA appeals and Form SSA-44