Medicare Part D

IRMAA & Medicare Part B and D in Las Cruces, N.M.

LAS CRUCES, N.M. — If you're on Medicare and your income has climbed in recent years, a letter from Social Security could be waiting for you this fall. It's called an IRMAA notice, and for a growing number of retirees in Doña Ana County, it means paying more each month for Part B and Part D in 2027.

Here's a plain-language guide to how the income-related surcharges work, where the thresholds fall, and what to do if your income has dropped since the tax return Medicare is using.

What IRMAA actually is

IRMAA stands for the Income-Related Monthly Adjustment Amount. It's an extra charge added to your standard Part B premium and your Part D drug plan premium if your income is above a set level.

A few things that trip people up:

• IRMAA is not a tax and it's not part of your plan's price. It's a Medicare surcharge set by the federal government.
• Social Security usually collects it directly from your monthly benefit.
• It applies whether you have Original Medicare or a Medicare Advantage plan that includes drug coverage.

The income Medicare uses is not this year's

This is the part that surprises Las Cruces retirees most. For your 2027 surcharge, Medicare looks at your 2025 tax return — the most recent one on file with the IRS. Specifically, it uses your modified adjusted gross income (MAGI), which is your AGI plus any tax-exempt interest.

So a one-time bump in 2024 — selling a house, a large Roth conversion, cashing in an investment — can raise your Medicare costs two years later, even if your income is back to normal now.

The 2027 income thresholds

For 2026, IRMAA kicks in above $109,000 for a single filer and $218,000 for a married couple filing jointly, based on 2024 income. Above those first thresholds, the surcharge rises in tiers, with the highest tier applying to single filers with income at or above roughly $500,000 (and $750,000 for joint filers).

Both Part B and Part D have their own surcharge amounts, but they use the same income brackets. If you cross a threshold, expect an adjustment to both.

The 2027 IRMAA bracket and surcharge amounts are set by the Centers for Medicare & Medicaid Services and typically posted on medicare.gov later in the fall, usually in November. It's worth checking there for the current dollar figures before you plan around them.

What to do if your income has dropped

If you've had a life-changing event since 2024, you can ask Social Security to use more recent income instead. 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 due to sale)

The form is SSA-44, "Medicare Income-Related Monthly Adjustment Amount – Life-Changing Event." You can file it with documentation (like a letter from your former employer) at the Social Security office. There's an SSA field office in Las Cruces on North Solano Drive that handles these requests.

Don't just ignore the IRMAA letter — appeal it if the facts have changed.

How this fits with the rest of your 2027 Medicare costs

A few other numbers worth keeping in mind as you plan:

• Part D out-of-pocket cap: $2,100 in 2026 and $2,400 in 2027. Once your drug spending hits that, you pay nothing for covered drugs the rest of the year.
• Part D maximum deductible: $615 in 2026 and $700 in 2027.
• Coverage gap ("donut hole"): gone as of 2025. Part D now has three phases instead of four.
• Medicare Prescription Payment Plan: an optional program that lets you spread your drug costs into monthly payments rather than paying a big bill at the pharmacy counter.

Las Cruces sits in Doña Ana County, and plan availability — the number of Medicare Advantage and stand-alone Part D plans you can choose from — is set at the county level. The 2027 lineup is described in each plan's Annual Notice of Change and on the plan finder at medicare.gov. If you're comparing options during Annual Enrollment (Oct. 15 – Dec. 7) or the Medicare Advantage Open Enrollment Period (Jan. 1 – March 31), the plan finder will show what's available at your ZIP code.