Medicare Part D

How Past Tax Returns Raise 2027 Medicare Premiums in Biloxi

BILOXI, Miss. — As Medicare's fall Annual Enrollment Period runs through Dec. 7, higher-earning retirees on the Gulf Coast are getting a fresh look at how their past tax returns can quietly raise their 2026 premiums. The extra charge, called the Income-Related Monthly Adjustment Amount, or IRMAA, is added on top of standard Part B and Part D premiums — and for 2026, it kicks in once a single filer's income tops $109,000.

What IRMAA is, in plain English

Most people on Medicare pay the standard Part B premium and whatever their Part D drug plan charges. But if your income is above a certain level, Medicare adds a surcharge to both. That surcharge is IRMAA.

It is not a penalty for doing anything wrong. It's simply a sliding scale: the higher your income, the more you pay each month toward Part B (doctor visits and outpatient care) and Part D (prescription drugs). The surcharge is billed by Medicare, not by your drug plan.

The income thresholds for 2027

For 2026, IRMAA begins when your modified adjusted gross income (MAGI) is more than:

• $109,000 if you file taxes as a single individual.
• $218,000 if you are married and file jointly.

Above those cutoffs, there are five tiers. Each tier adds a larger amount to both your Part B premium and your Part D premium. The very top tier applies to single filers with income at or above $500,000 and joint filers at or above $750,000. Medicare.gov publishes the full tier chart each year once figures are finalized.

Married couples who file separately have their own, tighter rules — the surcharge can start at a much lower income level, so it's worth checking directly with Social Security if that's your situation.

Why your 2025 tax return matters now

Here's the part that surprises people: Social Security doesn't use your current income to set your premium. It uses your most recent tax return on file, which for 2027 premiums generally means your 2025 return.

So a big one-time event in 2025 — selling a house, cashing out an investment, taking a large IRA withdrawal — could push you into an IRMAA tier for 2027 even if your income is much lower today. It's worth pulling out your 2025 return this fall and running the numbers before you get a premium notice in December or January.

If your income has gone down, you can appeal

Social Security allows an appeal if you've had a "life-changing event" that reduced your income. Qualifying events include:

• Retirement or reduced work hours
• Marriage, divorce, or the death of a spouse
• Loss of pension income
• Loss of income-producing property due to a disaster or other events outside your control

You file Form SSA-44 with documentation. If approved, Social Security uses your more recent, lower income instead of the older tax return. Given hurricane season realities along the Mississippi Gulf Coast, the disaster-related provisions are worth knowing about.

How this fits with the rest of your 2027 costs

IRMAA sits on top of two big Part D changes already in place for 2026:

• The annual out-of-pocket cap for Part D drugs is $2,100 in 2026 ($2,400 in 2027). Once you hit that, you pay $0 for covered drugs the rest of the year.
• The maximum Part D deductible is $615 in 2026 ($700 in 2027), though many plans set it lower.
• The old coverage gap (the "donut hole") was eliminated in 2025. Part D now has three phases: deductible, initial coverage, and catastrophic.
• The Medicare Prescription Payment Plan lets you spread your drug costs across the year in monthly installments instead of paying a large amount at the pharmacy counter.

None of those figures change based on your income — but your IRMAA surcharge is separate and will show up on your monthly bill.

What Biloxi residents can do this fall

Biloxi is in Harrison County, where beneficiaries have access to the standard Medicare enrollment periods:

• Annual Enrollment Period: Oct. 15 – Dec. 7 (change Part D or Medicare Advantage plans)
• Medicare Advantage Open Enrollment: Jan. 1 – March 31 (one switch allowed if you're already in an Advantage plan)

If you think IRMAA might affect you in 2027, a few practical steps:

1. Review your 2025 tax return and estimate your MAGI. 2. Watch for a notice from Social Security — usually mailed in late fall or early winter — that spells out your 2027 premium. 3. If a life-changing event applies, download SSA-44 from ssa.gov and gather your documentation. 4. Call Mississippi's State Health Insurance Assistance Program (SHIP) for free one-on-one help. It is not tied to any insurance company.