Medicare 2026

Miss Medicare's Deadlines and the Penalty Can Follow You for Life

DES MOINES, Iowa — For most people turning 65 in Polk County, Medicare enrollment is a one-time task with a small window. Miss that window, and the cost can shadow you for the rest of your life in the form of a monthly penalty that never goes away.

The rules around Part B and Part D late enrollment are strict, but they are also predictable. Once you know which dates apply to you, avoiding a lifetime surcharge usually comes down to marking a calendar.

The 7-month window that starts it all

Your Initial Enrollment Period (IEP) opens three months before the month you turn 65, includes your birthday month, and closes three months after. That's seven months total to sign up for Part A, Part B, and — if you want drug coverage — a Part D plan.

Sign up in the three months before your birthday month, and coverage starts the month you turn 65. Wait until later in the window, and coverage starts the month after you enroll.

If you miss the IEP entirely and you don't qualify for a Special Enrollment Period (more on that below), you may have to wait for the General Enrollment Period, which runs January 1 through March 31 each year, with coverage starting the month after you sign up.

How the Part B penalty is calculated

The Part B late enrollment penalty is 10% of the standard Part B premium for each full 12-month period you were eligible but didn't sign up. It's not a one-time charge. It's added to your monthly premium for as long as you have Part B — which, for most people, means for life.

So a two-year delay generally means a 20% higher Part B premium every month, permanently. A four-year delay means 40% more, and so on. The clock keeps ticking whether you realize it or not.

How the Part D penalty is calculated

Part D uses a different formula. The penalty is 1% of the "national base beneficiary premium" for every month you went without creditable prescription drug coverage after your IEP ended. ("Creditable" means coverage — often from an employer or union plan — that Medicare considers at least as good as a standard Part D plan.)

That amount is added to your Part D premium each month, and like Part B, it usually sticks for as long as you're enrolled in Part D. Even people who don't take medications should think carefully before skipping Part D, because signing up years later can be expensive.

Other Part D rules to keep in mind: the maximum deductible is $615 in 2026 and $700 in 2027, and out-of-pocket drug spending is capped at $2,100 in 2026 and $2,400 in 2027. The old coverage gap ("donut hole") was eliminated in 2025.

Special Enrollment Periods — the built-in escape hatches

Not everyone signs up at 65, and Medicare knows that. If you're still working and covered by a qualifying employer group health plan (generally at an employer with 20 or more employees), you can usually delay Part B and Part D without penalty.

When that coverage ends, two clocks start:

• Part B: You have an 8-month Special Enrollment Period beginning the month after your employment or the group coverage ends, whichever comes first.
• Part D: You have 63 days from the end of your creditable drug coverage to join a Part D plan.

These windows do not line up. The Part D window is much shorter, and missing it is one of the most common ways people accidentally trigger a lifetime penalty. COBRA and retiree coverage generally do not count as active employer coverage for the Part B rules, even though they may still be creditable for Part D.

The annual dates worth writing down

Two other windows matter after you're enrolled:

• Medicare Annual Enrollment Period: October 15 – December 7. This is when you can join, switch, or drop a Medicare Advantage or Part D plan for the following year.
• Medicare Advantage Open Enrollment Period: January 1 – March 31. If you're already in a Medicare Advantage plan, you can switch to another one or return to Original Medicare during this window.

Neither of these fixes a missed IEP for Part B — that's what makes the initial timing so important.

Where to check your own dates

Des Moines is in Polk County, and plan availability is set at the county level, so a licensed agent or a SHIP counselor can walk you through what's offered locally. But the enrollment deadlines themselves are federal, and they apply the same way whether you live in Des Moines, Ankeny, or West Des Moines.

For personalized answers about your own situation — especially if you're weighing whether to delay Part B because you're still working — talk to someone before the window closes, not after.

• Medicare: medicare.gov or 1-800-MEDICARE (1-800-633-4227), 24 hours a day, 7 days a week.
• Iowa SHIIP (State Health Insurance Assistance Program): free, unbiased Medicare counseling from trained volunteers.
• Social Security: ssa.gov or 1-800-772-1213, since Part B enrollment is handled through Social Security.