Medicare 2026

Missed Your Medicare Sign-Up Window? Here's How the General Enrollment Period Works

If you didn't sign up for Medicare when you were first supposed to, you're not stuck waiting forever. Medicare sets aside a yearly window called the General Enrollment Period (GEP) for people who missed their Initial Enrollment Period and don't qualify for a Special Enrollment Period. Here's a plain-English walk-through of how it works, what late sign-up can cost, and what to do next.

Who the General Enrollment Period is for

The GEP is designed for people who need Part A (when they have to buy it, meaning they don't qualify for premium-free Part A) or Part B, missed their Initial Enrollment Period around their 65th birthday, and don't have a Special Enrollment Period they can use instead.

If any of these describe you, the GEP is likely your path:

• You turned 65 some time ago and never enrolled in Part B.
• You have to pay a premium for Part A and never signed up.
• You dropped Part B at some point and now need it back, with no qualifying coverage in the gap.

If you've been covered by a group health plan based on your own or a spouse's current employment, you probably don't need the GEP. That coverage usually lets you delay Part B and sign up later through a Special Enrollment Period without owing the Part B late penalty.

The dates and how coverage starts

The GEP runs January 1 through March 31 every year. Since January 1, 2023, the rule for when coverage begins has been simple: your Part A and/or Part B coverage starts the first day of the month after you sign up. So if you enroll in February, your coverage begins March 1. If you enroll in March, it begins April 1.

That change matters. In the past, people who enrolled during the GEP sometimes waited months for coverage to begin. Today, the delay is much shorter.

The Part B late-enrollment penalty

The most important cost to understand is the Part B late-enrollment penalty. It's 10 percent of the standard Part B premium for every full 12 months you could have had Part B but didn't (and didn't have other qualifying coverage during that stretch). In most cases, you pay that penalty for as long as you have Part B — it doesn't go away after a few years.

A quick example of how the math works: if you went without Part B for two full years when you should have been enrolled, your penalty would be 20 percent added to the standard premium each month.

The exact dollar amount depends on the Part B standard premium for the year. CMS typically announces the following year's Part B standard premium and deductible in the fall (usually November). The 2027 Part B figures and the 2027 IRMAA income brackets have not been announced yet, so there's no reliable number to quote until CMS releases them. You can check Medicare.gov once they're published.

What about Part D and prescription drug coverage?

Part D (prescription drug coverage) has its own late-enrollment penalty, separate from Part B. If you went 63 days or more in a row without creditable drug coverage after you were first eligible, you may owe a Part D penalty when you eventually enroll. The penalty is tied to the Part D "base beneficiary premium," which for 2027 is $41.33 — a national figure used only to calculate the penalty. Actual Part D plan premiums are set by each plan.

A couple of national Part D facts worth knowing for 2027:

• The out-of-pocket cap for covered drugs is $2,400 (it is $2,100 in 2026).
• The most any Part D plan may charge as a deductible is $700.

After the GEP: choosing how to get your coverage

Once you've enrolled in Parts A and B, you'll generally have two broad paths for the rest of your Medicare coverage. The right fit depends on your health, budget, preferred doctors, and how you like to handle paperwork.

• Original Medicare (Parts A and B), often paired with a stand-alone Part D plan and, if you choose, a Medigap (Medicare Supplement) policy. This path typically offers broad provider access nationwide and more predictable out-of-pocket costs with Medigap, but you may pay a separate Medigap premium.
• A Medicare Advantage plan (Part C), which bundles Parts A and B and usually Part D, often with extra benefits. Advantage plans typically use provider networks and may require referrals or prior authorization, with costs structured as copays and an annual out-of-pocket maximum.

Neither path is "better" in the abstract. It depends on your situation. The Annual Enrollment Period from October 15 to December 7, 2026 is when you can pick or change Medicare Advantage and Part D coverage for 2027, with your choices taking effect January 1, 2027.

A note for people with Medicaid or Extra Help

If you have full Medicaid or qualify for Extra Help with Part D costs, you have more flexibility than most. Since 2025, you've had a monthly Special Enrollment Period to move to Original Medicare paired with a stand-alone Part D plan, or to switch stand-alone Part D plans. And if you're a full-benefit dual-eligible, you can join an integrated Dual Eligible Special Needs Plan (D-SNP) in any month of the year.

One more cost note

The Social Security Administration announced on October 14, 2026 a 3.6 percent cost-of-living adjustment (COLA) for benefits payable beginning January 2027. That affects Social Security checks, not Medicare premiums directly, but many people have their Part B premium deducted from their Social Security benefit, so it's useful context.

Where to go next

Medicare rules can feel dense, but you don't have to figure them out alone. For official, personalized information, visit Medicare.gov or call 1-800-MEDICARE (1-800-633-4227), available 24 hours a day, seven days a week. If you missed your window, enrolling as soon as the GEP opens on January 1 is usually the fastest way to get covered and limit any penalty from growing further.