Medicare General Enrollment Period Deadlines & Penalties
September 1, 2026
The Medicare General Enrollment Period (GEP) runs from January 1 to March 31 every year and exists as a fallback for people who missed their Initial Enrollment Period (IEP), the 7-month window around your 65th birthday, and don't qualify for a Special Enrollment Period (SEP). If you sign up for Part A or Part B during the GEP, your coverage now starts the first day of the month after you enroll, and you may owe a permanent late enrollment penalty for the months you went without coverage. This guide walks through the exact 2026 deadlines, how penalties are calculated for Part A, Part B, and Part D, and what to check before you enroll.
Quick Answer
The Medicare General Enrollment Period runs January 1, March 31 each year for people who missed their Initial Enrollment Period and have no Special Enrollment Period available. Coverage begins the first day of the month after you sign up. If you delayed Part B, you'll typically pay a 10% premium penalty for each full 12-month period you were eligible but not enrolled, and it lasts as long as you have Part B. A similar permanent penalty applies to Part D if you go 63 or more days without creditable drug coverage.
Who Needs to Use the General Enrollment Period
Most people first become eligible for Medicare during their IEP, a 7-month window that starts 3 months before the month you turn 65. Those who miss it can often still enroll through an SEP if they had health coverage through a current employer, see Medicare special enrollment period qualifying events for the details, including guidance on enrolling in Medicare after losing employer coverage.
The GEP is for everyone else: people who simply didn't sign up when they were first eligible and don't have an SEP to fall back on. If that describes your situation, or you're helping a family member sort out what happened after turning 65 health coverage decisions were missed, the GEP is your next opportunity to enroll.
2026 General Enrollment Period Deadline
The GEP opens January 1, 2026, and closes March 31, 2026, the same three-month window every year. As of a rule change that took effect in 2023, coverage now starts the first day of the month after you enroll, rather than being delayed until July 1 as it was under the old rule. That means enrolling in January gets you coverage in February, while waiting until March pushes your start date to April. According to Medicare.gov, this faster start date applies to anyone who signs up for Part A or Part B during the GEP.
General Enrollment Period Action Checklist
- Confirm you don't qualify for a Special Enrollment Period before assuming you need the GEP
- Enroll in Part A and/or Part B through the Social Security Administration between January 1 and March 31
- Ask specifically when your coverage will start based on the month you enroll
- If you're signing up for Part B for the first time, also compare Medicare Advantage and Part D drug plan options right away
- Ask Social Security to calculate any Part A or Part B late enrollment penalty before you finalize enrollment
How the Part B Late Enrollment Penalty Works
The Part B penalty is 10% of the standard monthly premium for each full 12-month period you were eligible for Part B but didn't enroll and didn't have qualifying coverage. This penalty is added to your premium for as long as you have Part B, it does not expire. For example, someone who waited three full years (36 months) past their IEP to enroll would pay a 30% penalty on top of the standard Part B premium every month going forward.
Part A Penalty (Less Common)
Most people get Part A premium-free because of their work history, so no penalty applies. If you're one of the smaller group who has to buy Part A, delaying enrollment adds a 10% penalty to your premium, and you pay that higher amount for twice the number of years you could have had Part A but didn't.
How the Part D Late Enrollment Penalty Works
If you go 63 or more days without Part D coverage or other creditable drug coverage (coverage that pays, on average, at least as much as Medicare's standard drug plan) after your IEP ends, you'll generally owe a Part D penalty. It's calculated as 1% of the national base beneficiary premium for each full month you went without coverage, and it's added to your Part D premium permanently. According to Medicare.gov, this penalty amount changes annually along with the base premium, so it's worth confirming the current figure before you enroll. For a fuller breakdown of how these penalties stack and how to check your own timeline, see medicare late enrollment penalty.
GEP and Penalty Basics at a Glance
Don't Confuse the GEP With the MA Open Enrollment Period
The Medicare Advantage Open Enrollment Period also runs January 1, March 31, but it's a different tool with a different audience: it lets people already enrolled in a Medicare Advantage plan switch plans or return to Original Medicare. The GEP is specifically for enrolling in Part A and/or Part B for the first time. Mixing these up is a common source of confusion, see Medicare enrollment periods explained for a full side-by-side breakdown.
How to Avoid Needing the GEP Next Time
The best way to avoid a late enrollment penalty is to enroll during your IEP or, if you have qualifying employer coverage, to use your SEP promptly once that coverage ends. If you're weighing whether to delay Part B because you still have job-based coverage, review how to delay Medicare Part B without penalty before you make that call, since not every employer plan qualifies you for a penalty-free delay. And once you're enrolled, understanding when can I switch Medicare plans helps you avoid missing future deadlines for coverage changes.
Get free help sorting out your Medicare timing
If you're not sure whether you need the General Enrollment Period, qualify for a Special Enrollment Period, or are facing a penalty, get plain-language guidance on your specific situation. No pressure.
Frequently Asked Questions
Yes. If you enroll in Part B for the first time during the GEP, you can also enroll in a Medicare Advantage plan or a standalone Part D drug plan, with coverage typically aligned to your new Part B start date. Confirm the exact window with Medicare.gov or Social Security when you enroll.
No. Both run January 1, March 31, but the GEP is for enrolling in Part A or Part B for the first time, while the Medicare Advantage Open Enrollment Period is only for people already enrolled in a Medicare Advantage plan who want to switch plans or return to Original Medicare.
Generally, no. Once assessed, the Part B penalty is added to your premium for as long as you have Part B. In limited cases, such as a documented enrollment error by the government, Social Security may correct or waive a penalty, that determination is made case by case.
Creditable coverage is drug coverage, such as certain employer, union, or VA plans, that's expected to pay, on average, at least as much as Medicare's standard Part D coverage. Your plan administrator should tell you each year whether your coverage qualifies as creditable.
You'll need to wait for the next year's GEP (January 1, March 31) to enroll in Part A or Part B, unless a Special Enrollment Period applies to your situation in the meantime.