Are you eligible for a Medicare special enrollment period?

The eligibility rules vary for Medicare Parts A and B, Medicare supplement insurance, Medicare Advantage and Medicare Part D

In this article:

• What is a Medicare special enrollment period?
• Who qualifies for a Medicare special enrollment period?
• Medicare Part B (and Premium Part A) special enrollment periods
• Is there a special enrollment period for Medicare Part A?
• Medicare Advantage and Medicare Part D special enrollment periods
• Medigap special enrollment periods
• Frequently asked questions about Medicare special enrollment periods

What is a Medicare special enrollment period?

Like other types of health insurance, each of the various types of Medicare has a special enrollment period (SEP) that’s triggered by various qualifying life events. SEPs allow a person to sign up for coverage outside of the usual initial enrollment or annual open enrollment windows.

But the Medicare SEP rules vary depending on the type of coverage. So if you’ve moved, or retired and strategically delayed your enrollment, a Medicare SEP might be helpful, giving you flexibility when events in your life affect your coverage needs.

Who qualifies for a Medicare special enrollment period?

The eligibility rules for a Medicare SEP differ for each type of coverage, but the life events that make a beneficiary eligible may include (depending on the type of coverage): a change in residence, a change in eligibility for Extra Help, loss of coverage due to a change in employment, or Medicare plan contract changes. Life events that may trigger an SEP for each type of coverage are listed in the sections below.

Medicare Part B (and Premium Part A) special enrollment periods

If you’re aging into Medicare, you can enroll during your seven-month initial enrollment period that begins three months before the month you turn 65. 1 If you miss that window, you have an annual opportunity to sign up for coverage during the January – March general enrollment period 2 . (A late-enrollment penalty will apply if you’ve delayed your enrollment by 12 months or more from when you were initially eligible.)

But if you qualify for a special enrollment period, you don’t have to wait for the general enrollment period to sign up for coverage, and you may also be able to avoid late-enrollment penalties. Some eligibility requirements for a special enrollment period have been available for many years, while others became available as of 2023 under rules that were finalized in 2022. 3

This special enrollment period allows a person to sign up for Medicare Part B, Premium Part A, or both. Most people do not have to pay a premium for Medicare Part A, and can enroll in that coverage any time after they become eligible. 4 A special enrollment period is only necessary for Medicare Part A if you have to pay a premium for it. It’s called “Premium Part A” if you have to pay a premium for the coverage.

Here’s a list of life events that may make you eligible for a special enrollment period:

• You delayed enrollment because you had active employee coverage. A special enrollment period for Medicare Part B (and Premium Part A) is available if you’ve delayed your enrollment because you (or your spouse) are still working and you’re covered by an employer’s group health plan. You can enroll in Part B at any point while you still have coverage under that plan as an active employee or spouse of an active employee. And the special enrollment period continues for eight months after the final month of employment or coverage. Learn more about how you can delay enrollment in Part B without a penalty. For most Medicare beneficiaries, there’s no premium for Medicare Part A, and thus no reason to delay enrollment. (You can’t contribute to an HSA once you’re enrolled in any part of Medicare, so some people do delay enrollment in Part A in order to continue to contribute to an HSA.)But Part B has a monthly premium ($174.70/month for most enrollees in 2024) 5 so people do sometimes choose to delay enrollment in Part B. As long as they’re covered under an employer’s health plan as an active employee or spouse of an active employee, they will have an opportunity to sign up for Part B during a special enrollment period once they no longer have active employee coverage.
• You delayed enrollment because you were volunteering overseas. There is also a Part B (and Premium Part A) special enrollment period for a person who was serving overseas for at least 12 months as a volunteer with a 501(c)(3) tax exempt organization when they first became eligible for Medicare, assuming they had health coverage during the time they were volunteering. They have a six-month window, starting when they return to the U.S., during which they can enroll in Medicare.
• You delayed enrollment because you had TRICARE. There is a 12-month special enrollment period for people with TRICARE coverage who become eligible for Medicare prior to age 65, but don’t enroll when they’re first eligible. The special enrollment period begins when their initial enrollment period ends and continues for 12 months.
• You didn’t enroll due to an emergency or disaster. If you missed your initial Medicare enrollment period, general enrollment period, or a special enrollment period for which you were eligible, because you were affected by a government-declared emergency or disaster, you may qualify for a special enrollment period that begins on the day the disaster is declared (or the start date identified in the disaster declaration, if that’s earlier) and lasts for six months after the end of the emergency/disaster declaration. 6
• You didn’t enroll because you relied on materially incorrect information. A special enrollment period may be available if you didn’t enroll in Medicare during your initial enrollment period, the general enrollment period, or a special enrollment period for which you were eligible because you were given materially incorrect information by your employer, group health plan, or agent/broker representing the group health plan. The special enrollment period lasts for six months, starting with the date you notify the Social Security Administration of the error.
• You didn’t enroll because you were incarcerated. You may be eligible for a special enrollment period when you’re released from incarceration, after either becoming eligible for Medicare while incarcerated, or losing Medicare during incarceration, and failing to enroll or reenroll due to being incarcerated. The special enrollment period continues for 12 months beginning on the day you’re released. Note that the Social Security Administration defines “incarcerated” as being “in custody of penal authorities.” 7
• You didn’t enroll because you had Medicaid. You’ll have a special enrollment period if you didn’t enroll in Medicare when you were first eligible because you were enrolled in Medicaid and the Medicaid coverage was allowed to continue. This was the case for some people during the COVID pandemic, when Medicaid disenrollments were generally prohibited. The special enrollment period lasts for six months after Medicaid ends.
• Exceptional extenuating circumstances prevented your enrollment. The Social Security Administration may grant a special enrollment period on a case-by-case basis for people who had extenuating circumstances that prevented them from enrolling in Medicare during a normal enrollment opportunity.

Any special enrollment right to sign up for Medicare Part B (and Premium Part A) will allow you to choose either Original Medicare or Medicare Advantage.

Is there a special enrollment period for Medicare Part A?

A special enrollment period for Medicare Part A is only necessary if you’d have to pay a premium to enroll in Part A. About 99% of Medicare beneficiaries do not have to pay a premium for Part A. 8 For these individuals, enrollment in Part A is available starting when they’re first eligible or any time after that. 4 Your coverage effective date may be backdated by up to six months (but no earlier than the month you were first eligible).

Medicare Advantage and Medicare Part D special enrollment periods

If you’re enrolled in a Medicare Advantage or Medicare Part D prescription drug plan, you can make changes to your coverage during Medicare open enrollment each fall.

But there are a variety of qualifying life events that allow you to switch to a different plan outside of the annual election period. (Depending on the circumstances, there may also be an option to switch to Original Medicare.) Here are situations considered qualifying life events that may trigger a SEP:

• You make a permanent move. You move to a location that’s either outside your plan’s service area, or to an area where there are other Medicare Advantage or Part D plans available. It can also be a move back into the United States after living abroad, a move into or out of an institution, or your release from incarceration. In general, the special enrollment period continues for two months after your move, and it can also start the month before, depending on the circumstances.
• You lose other health coverage. The coverage you’re losing can be Medicaid, or employer or union-sponsored coverage (including COBRA). It can also be involuntary loss of other creditable drug coverage, or leaving a Medicare Cost Plan or Program for All-Inclusive Care for the Elderly (PACE) plan. In general, your special enrollment period will last for at least two months after the other coverage ends. You’ll have the opportunity to join a Medicare Advantage or Part D plan, or, if applicable, switch to a different plan.
• You have an opportunity to enroll in other coverage. This could be an opportunity to enroll in an employer’s plan, an opportunity to enroll in other creditable drug coverage, or enrolling in a PACE plan. You have a special enrollment period that will allow you to drop your current Medicare Advantage or Part D plan and switch to the other coverage. You can do this during whatever window of opportunity you have to enroll in the other coverage.
• Your plan’s contract with Medicare is terminated, non-renewed, orsanctioned. You’ll have an opportunity to enroll in a different Medicare Advantage or Part D plan. If the contract isn’t renewed for the coming year, your SEP runs from December 8 to the last day of February. (You can also just use the fall open enrollment period (Medicare open enrollment) to pick a new plan). If the plan’s contract terminates mid-year, your SEP begins two months before the termination date, and continues for another month afterward. In the case of a contract sanction, the special enrollment opportunity will be determined by CMS on a case-by-case basis.
• You have both Medicare and Medicaid. This gives you an opportunity to join, switch, or disenroll from a Medicare Advantage or Part D plan up to one time per quarter. (For the final quarter of the year, the regular October 15 – December 7 annual election period applies instead).
• You’re eligible for Extra Help. This gives you a quarterly opportunity to join, switch, or disenroll from a Part D plan (for the final quarter of the year, the regular October 15 – December 7 annual election period applies instead).
• You’re enrolled in a State Pharmaceutical Assistance Program (SPAP). You have one annual opportunity to enroll in a Part D plan or a Medicare Advantage plan that includes Part D coverage.
• You have a chronic, severe, or disabling medical condition and there’s aspecial needs plan (SNP)available in your area for people with your medical condition. You can switch to that plan at any time. On the other hand, if you’re enrolled in an SNP and then you no longer have the condition that the SNP is designed to serve (or are no longer eligible for Medicaid, if you’re in a dual-eligible SNP for people with Medicare and Medicaid), you can transition away from the SNP and to another Medicare Advantage or Part D plan. Your window to do this begins when you no longer meet the SNP’s requirements, and continues for three months after the SNP’s grace period ends. (SNP grace periods for people who no longer meet the eligibility guidelines last at least one month.)
• You received erroneous advice or information. This can include the fact that you enrolled in (or didn’t enroll in) a plan due to a federal employee’s error, action, or inaction. The SEP will allow you to join, switch, or drop your Medicare Advantage or Part D plan. Or it could be a situation in which you weren’t informed that your private drug coverage wasn’t as good as Medicare coverage (wasn’t creditable) or you weren’t informed that you would be losing creditable drug coverage. In either of those two scenarios, you’ll have a special enrollment right to enroll in Part D coverage, either as a stand-alone plan or as part of a Medicare Advantage plan. Your enrollment window begins the month CMS approves the SEP and continues for two more months after that. 9

Medigap special enrollment periods

Medigap (Medicare supplement insurance) is unique among the various types of Medicare coverage, in that it does not have a federally mandated annual enrollment period.

Some states do have limited annual enrollment opportunities, but federal rules only require all Medigap plans to be guaranteed issue (meaning eligibility and premium do not depend on medical history) during a six-month window that starts with your Part B effective date, assuming you’re at least 65 years old. ( You must also have Medicare Part A to buy a Medigap plan.

After that, Medigap insurers in most states can use medical underwriting when a person applies for Medigap coverage. That means the insurer can reject the application or offer a policy with a higher premium, depending on the person’s medical history.

But there are certain situations where an insurance company can’t deny you a Medigap policy (or charge higher premiums based on medical underwriting), which are referred to as guaranteed-issue rights. (Unlike other types of Medicare coverage, a beneficiary can apply for a Medigap plan at any time, but the insurer can use medical underwriting if the person doesn’t have a guaranteed-issue right.)

In general, the guaranteed-issue special enrollment period continues for 63 days after the qualifying event, and in some cases it’s also available starting 60 days before the qualifying event. In most cases, a guaranteed-issue right will only allow you to enroll in Medigap Plan A, B, C, D, F, G, K, or L, as opposed to any available Medigap plan. (Note that regardless of the circumstances, Plans C and F can only be purchased by people who became eligible for Medicare prior to 2020.) 10

There are a variety of qualifying events that result in a federal Medigap guaranteed-issue right. They include:

• Trial right when you opted for Medicare Advantage initially: You joined a Medicare Advantage or PACE plan when you were first eligible for Medicare, and you’ve been enrolled in that plan for less than a year. You’re in your trial right period and have the option to switch to any available Medigap plan.
• Trial right when you dropped Medigap to enroll in Medicare Advantage: You dropped a Medigap policy and switched to a Medicare Advantage plan for the first time and have been enrolled in the new plan for less than a year. You’re in your trial right period and can switch back to the Medigap plan you had before. If it’s no longer available, you can switch to any available Medigap Plan A, B, C, D, F, G, K, or L.
• Medicare Advantage plan no longer available: You have Medicare Advantage and your plan terminates its contract with Medicare, stops offering coverage in your area, or you move out of the plan’s service area. You have the right to buy any available Medigap Plan A, B, C, D, F, G, K, or L.
• Other health coverage is ending. You have Original Medicare and employer-sponsored coverage (including COBRA) and the employer-sponsored plan is ending. You have the right to buy any available Medigap Plan A, B, C, D, F, G, K, or L.
• Moving out of your Medicare SELECT plan’s service area.Medicare SELECT is a type of Medigap that has a localized provider network. If you have this type of coverage and move out of the plan’s service area, you have the right to buy any available Medigap Plan A, B, C, D, F, G, K, or L.
• Involuntary loss of your Medigap coverage. If you lose your coverage through no fault of your own, (for example, your Medigap carrier goes bankrupt), you have the right to buy any available Medigap Plan A, B, C, D, F, G, K, or L. (Note that loss of coverage due to failure to pay premiums does not trigger a special enrollment period.)
• Rule breach by your Medicare Advantage or Medigap plan. If you left your Medicare Advantage or Medigap plan because the plan misled you or didn’t follow Medicare’s rules, you have the right to buy any available Medigap Plan A, B, C, D, F, G, K, or L. 11 To request a special enrollment period in this situation, you will need to call 1-800-MEDICARE and explain how you were misled or how the plan didn’t follow Medicare’s rules.

As noted above, some of these qualifying events will also trigger a special enrollment period to sign up for a Medicare Advantage plan. You’ll want to consider the pros and cons of Medigap plus Part D versus Medicare Advantage before making your decision.

Frequently asked questions about Medicare special enrollment periods

What happens if you miss your Medicare SEP window?

If you miss your Medicare SEP window, you won’t be able to enroll or make a plan change until the next general enrollment period (for Medicare Part B or Premium Part A) or annual election period (for Medicare Advantage or Medicare Part D). And there is no annual enrollment opportunity for Medigap, so you may not have another opportunity to enroll in Medigap or pick a different Medigap plan that is guaranteed-issue.

Will I be charged a late-enrollment penalty for enrolling during an SEP?

There are only potential late-enrollment penalties for Medicare Part B (and Premium Part A) and Part D.

In general, a Part B (and Premium Part A) special enrollment period will allow you to sign up without a late enrollment penalty.

There is a Medicare Part D late enrollment penalty if you go without creditable drug coverage for 63 days or more. But the circumstances that trigger a Part D special enrollment period generally either involve switching from one Part D plan to another (meaning you didn’t have a gap in coverage), or have an exemption from the penalty (such as being eligible for Extra Help, in which case the penalty is waived).

What documentation do I need to provide when signing up during a Medicare SEP?

To use a Medicare SEP, you’ll generally need to provide various identification information along with proof of the specific situation that triggered the SEP.

This could include proof of other coverage termination, erroneous information that was provided to you by your employer, group health plan, or a Medicare representative, or exceptional circumstances that caused you to miss your initial enrollment window.

If you think you might be eligible for a Medicare SEP, you can call 1-800-MEDICARE to describe your situation. If an SEP is available to you, the representative will let you know what information you’ll need to provide in order to use it.

Louise Norris is an individual health insurance broker who has been writing about health insurance and health reform since 2006. She has written dozens of opinions and educational pieces about Medicare for medicareresources.org since 2013.

1. “Enrolling in Medicare Part A & Part B” p. 11, Medicare.gov, Accessed January 2024 ⤶
2. “Enrolling in Medicare Part A & Part B” p. 6, Medicare.gov, Accessed January 2024 ⤶
3. “SSA – POMS: HI 00805.382 – Special Enrollment Period (SEP) for Exceptional Conditions – 12/21/2022” SSA.gov. Dec. 21, 2022 ⤶
4. “When does Medicare coverage start?” Medicare.gov. Accessed January 2024 ⤶⤶
5. “2024 Medicare costs” Medicare.gov. Accessed January 2024 ⤶
6. “Exceptional Conditions Special Enrollment Period (SEP) for Individuals Impacted by an Emergency or Disaster Declared by Federal, State or Local Government Entities” SSA.gov. Accessed January 2024. ⤶
7. “Program Operations Manual System (POMS)” SSA.gov. Jan. 30, 2024 ⤶
8. “2024 Medicare Parts A & B Premiums and Deductibles” CMS.gov. Oct. 12, 2023 ⤶
9. “Code of Federal Regulations” ECFR.gov. Jan. 24, 2024 ⤶
10. “2023 Choosing a Medigap Policy” Medicare.gov. March 2023 ⤶
11. “Options for those who enrolled in a Medicare Advantage Plan by mistake or because of misleading information” Medicare Interactive. Accessed January 2024 ⤶

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