When You Can Sign Up for Medicare: The Three Enrollment Windows

The three enrollment periods and when each one opens

Medicare has three separate windows when you can sign up or change your coverage. Missing the window that applies to you can mean waiting months to enroll, or paying a penalty for the rest of your time on Medicare. The window you use depends on your age, your work status, and whether you already have coverage.

Initial Enrollment Period (IEP) is the first time you become may be able to access — usually when you turn 65. It runs for seven months: the three months before the month you turn 65, the month itself, and the three months after. If you miss this window and do not have other may have access to coverage, you will pay a permanent 10 percent penalty on your Part B premium for every 12 months you delayed.

General Enrollment Period (GEP) runs every year from January 1 to March 31. Anyone can sign up during this window, but it is meant for people who missed their Initial Enrollment Period. If you enroll during GEP, your coverage starts July 1. You may also pay a penalty if you did not have continuous coverage.

Special Enrollment Period (SEP) opens when certain life events happen — losing employer coverage, moving to a new state, getting married, or may have access to for Medicaid. The window is usually 60 days from the event, though some situations give you more time. SEP is the only way to enroll outside the regular windows without a penalty.

Key Takeaways

• Your Initial Enrollment Period is seven months long and centered on your 65th birthday; missing it triggers a permanent penalty on your Part B premium.
• General Enrollment Period runs January 1 to March 31 each year and is open to anyone, but coverage does not start until July 1.
• Special Enrollment Period opens after specific life events like losing employer coverage or moving states, and is the only penalty-free way to enroll outside regular windows.
• You can sign up through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.
• Penalties for missing your Initial Enrollment Period are permanent and calculated as a percentage of your Part B premium for each 12-month period you delayed.

Initial Enrollment Period: Your seven-month window at 65

Your Initial Enrollment Period starts three months before the month you turn 65 and ends three months after. If you turn 65 in June, for example, your window opens in March and closes in September. You do not have to wait until your birthday month to sign up — you can start as soon as the window opens.

The seven-month window is long enough to give you time, but short enough that missing it has real consequences. If you do not enroll during this period and you do not have other may have access to coverage (like an active employer health plan or TRICARE), you will owe a permanent penalty. The penalty is 10 percent of the Part B premium for each 12-month period you were may be able to access but not enrolled. If you delay three years, your penalty is 30 percent — and you pay it for life.

If you are still working and covered by your employer's health plan, you may have a different rule. Some employers allow you to delay Part B enrollment without penalty as long as you are actively employed and covered. When you leave that job, you get an eight-month Special Enrollment Period to sign up without penalty. You will need proof of your employer coverage — usually a letter from your employer or a copy of your health plan documents.

General Enrollment Period: January through March every year

General Enrollment Period is open every year from January 1 to March 31. Anyone can sign up during these three months, whether or not they missed their Initial Enrollment Period. This is the safety net for people who did not enroll at 65 and did not may have access to for a Special Enrollment Period.

The catch is timing. If you enroll during General Enrollment Period, your coverage does not start until July 1 of that same year. If you sign up in January, you have a six-month gap with no Medicare coverage. If you sign up in March, the gap is four months. You are responsible for any medical costs during that gap.

You may also owe a late enrollment penalty if you did not have continuous coverage before you sign up. The penalty is calculated the same way as the Initial Enrollment Period penalty — 10 percent of the Part B premium for each 12-month period you were may be able to access but not enrolled. Unlike the Initial Enrollment Period penalty, the GEP penalty is not permanent; it ends once you have been enrolled for 30 months without a break.

Special Enrollment Period: Signing up after a life change

A Special Enrollment Period opens when something changes in your life that affects your coverage. The most common trigger is losing employer health insurance — when you retire, get laid off, or your employer stops offering coverage. Other triggers include moving to a new state, getting married or divorced, gaining or losing Medicaid coverage, or becoming a U.S. citizen or permanent resident.

The window is usually 60 days from the event, though some situations are longer. If you lose employer coverage, you have 60 days from the date coverage ends. If you move states, you have 60 days from the date you move. If you turn 65 while still employed and covered, you have eight months from the date you leave that job or coverage ends, whichever comes first.

Special Enrollment Period is the only way to enroll outside the regular windows without a penalty. You will need to prove the event happened — a termination letter from your employer, a lease or utility bill showing your new address, a marriage certificate, or a Medicaid notice. Medicare will ask for this documentation when you sign up.

How to sign up during your enrollment period

You have three ways to sign up: online, by phone, or in person. The fastest is usually online through Medicare.gov. You can create an account, review your options, and submit your enrollment in one session. The website walks you through each step and tells you immediately if there are any documents you need to provide.

You can also call 1-800-MEDICARE (1-800-633-4227). Representatives are available seven days a week, and they can answer questions about which coverage you need and help you enroll over the phone. If you need an interpreter, they can provide one in most languages.

A third option is to visit your local Social Security office in person. You can find the nearest office on Social Security's website. Bring your Social Security card, proof of citizenship or legal residency, and proof of income if you are applying for help paying premiums. Walk-in appointments are available, though you may wait longer than if you call ahead.

What happens if you miss your enrollment period

If you miss your Initial Enrollment Period and do not have other may have access to coverage, you cannot sign up again until the next General Enrollment Period (January 1 to March 31). That could mean waiting up to 15 months with no Medicare coverage. During that time, you are responsible for all medical costs.

When you do sign up during General Enrollment Period, your coverage starts July 1. You will also owe a late enrollment penalty on your Part B premium. The penalty is 10 percent of the current Part B premium for each 12-month period you were may be able to access but not enrolled. If you were may be able to access for two years before signing up, your penalty is 20 percent of the premium — and you pay it every month for 30 months.

The only exception is if you have a may have access to life event that opens a Special Enrollment Period. If you lose employer coverage, move states, or experience another triggering event, you can sign up immediately without waiting for General Enrollment Period. This is why it is important to document any life changes that might may have access to you.

Penalties and how they are calculated

Late enrollment penalties are permanent for Part B and Part D (prescription drug coverage). Once you owe a penalty, you pay it every month for the rest of your time on Medicare. The penalty is not a one-time fee — it is added to your monthly premium.

For Part B, the penalty is 10 percent of the current standard premium for each 12-month period you delayed. The current standard Part B premium changes each year, so your penalty amount changes too. If the standard premium is $165 in one year and $170 the next, your 10 percent penalty adjusts accordingly.

For Part D (prescription drug coverage), the penalty is 1 percent of the national average premium for each month you delayed, rounded to the nearest dollar. If you delayed 24 months, your penalty is roughly 24 percent of the average premium. Like Part B, this penalty is permanent and recalculated each year as premiums change.

Part A (hospital insurance) does not usually have a late enrollment penalty if you have been covered by an employer plan. If you did not have employer coverage and you delay Part A enrollment, you may owe a 10 percent penalty, but it is temporary — it ends after you have been enrolled for 24 months.

Frequently Asked Questions

Can I change my mind after I sign up during my enrollment period?

Yes, but only during your enrollment period. If you enroll in Original Medicare and then change your mind, you can switch to a Medicare Advantage plan (or vice versa) as long as you are still within your enrollment window. Once your period ends, you are locked into your choice until the next General Enrollment Period in January.

What if I turn 65 while I am still working?

You can delay Part B enrollment without penalty as long as you are actively employed and covered by your employer's health plan. When you leave that job, you have eight months from the date coverage ends to sign up for Part B without penalty. You will need a letter from your employer confirming your coverage dates and that you were actively employed.

Do I have to sign up for Medicare at 65 if I do not want it yet?

If you are covered by an active employer plan, you can delay Part B without penalty. You do not have to sign up for Part A (hospital insurance) if you do not want it, but you will owe a penalty if you delay Part B and do not have may have access to coverage. If you are not working and not covered by an employer plan, you should sign up during your Initial Enrollment Period to avoid penalties.

What counts as a may have access to life event for Special Enrollment Period?

The most common events are losing employer coverage, moving to a new state, getting married or divorced, gaining or losing Medicaid, and becoming a U.S. citizen or permanent resident. Some situations like a change in income or a family member's death may also may have access to. Call 1-800-MEDICARE to ask whether your specific situation opens a Special Enrollment Period.

If I miss General Enrollment Period, when can I sign up next?

You have to wait until the next General Enrollment Period, which runs January 1 to March 31 of the following year. If you miss it in March, you cannot sign up again until January of the year after that — almost a full year away. The only exception is if you experience a may have access to life event that opens a Special Enrollment Period.