Medicare Supplement Insurance, more commonly known as Medigap, helps pay some of your out-of-pocket costs under Original Medicare (Parts A and B). The best time to buy a Medigap policy is during your Medicare Supplement Open Enrollment Period (OEP).

When is the Medicare Supplement Open Enrollment Period?

Your Medicare Supplement Open Enrollment Period begins the first day of the month you are age 65 or older AND enrolled in Medicare Part B. If you sign up for Medicare before your 65th birthday, during your Initial Enrollment Period, your Medigap OEP will start the month following your birth month.

Medigap Open Enrollment lasts for 6 months.

If you plan to keep Original Medicare, we nearly always recommend enrolling in a Medigap plan during your Medicare Supplement OEP. The only time we suggest waiting to buy a Medicare Supplement Insurance policy is if you have secondary coverage through an employer plan, retiree insurance, COBRA, or other form of creditable group health insurance.

Medical underwriting: Why you should sign up for Medigap during Open Enrollment

Your Medigap Open Enrollment Period is one of the few times your application does not undergo a process called medical underwriting.

Insurance companies use medical underwriting to determine how likely you are to file an insurance claim. (All insurance uses some type of underwriting process; it's how they determine your insurance rates and whether to sell you a policy.)

In medical underwriting, you answer a series of health-related questions, including:

• Age
• Weight
• Tobacco use
• Chronic health conditions
• Personal and family medical history
• Upcoming medical procedures

Depending on your answers, the insurance company may refuse to sell you a Medicare Supplement policy. Or, they may sell you a policy but charge you a higher premium. However, if you sign up for Medigap during your OEP, insurance companies cannot deny you a policy or charge you a higher rate, even if you have pre-existing conditions.

Our Find a Plan tool makes it easy to compare Medicare plans in your area. Just enter your location, estimated coverage start date, and hit Continue to review your Medigap plan options.

Are there other times you can buy a Medigap policy?

You may apply for a Medigap plan outside of Open Enrollment. Unless you qualify for guaranteed issue rights, though, your application will go through medical underwriting.

What are guaranteed issue rights?

Also known as Medigap protections, guaranteed issue rights are situations in which insurance companies must sell you a Medicare Supplement policy without charging a higher premium or refusing to cover pre-existing conditions.

Your Medicare Supplement Open Enrollment Period is the first time you have guaranteed issue rights. The next sections describe each situation that qualifies you for guaranteed issue rights and the guidelines surrounding those rights.

Please note that, in all of the following situations, you may only purchase a Medigap policy if you have or return to Original Medicare. In addition, Medigap Plan C and Medigap Plan F are no longer available to beneficiaries who became eligible for Medicare on or after January 1, 2020.

Medigap Plan G provides all of the same benefits that Plan F offered with the exception of the Medicare Part B deductible. Most beneficiaries find that their out-of-pocket costs under Plan G are lower, though, since Plan G nearly always has a lower premium.

Your Medicare Advantage Plan leaves Medicare OR stops servicing your area OR you move outside of your plan's service area

You qualify for guaranteed issue rights if you have a Medicare Advantage (MA) plan but lose coverage due to moving or changes to your plan. Guidelines include:

• The right to buy Medigap Plan A, B, C, D, F, G, K, or L from any insurance company that sells one or more of those plans in your state
• You may purchase your Medigap policy 60 days before you lose your MA coverage
• The window closes 63 days after your MA coverage ends

Your Medigap coverage will begin once your Medicare Advantage plan coverage ends.

You have Original Medicare plus secondary coverage and your secondary plan is ending

If you have Original Medicare plus secondary coverage through an employer-sponsored group health plan, COBRA, or similar insurance, you qualify for guaranteed issue rights when that coverage ends.

Your Medicare Supplement plan purchase options include Plans A, B, C, D, F, G, K, and L. Please note that not all insurance companies sell every Medigap plan.

You have 63 days to purchase one of these plans. Your purchase window opens on the latest of the following dates:

• The date your secondary coverage ends
• The date printed on the notice you receive that your coverage is ending, assuming you receive notification
• The date your claim is denied, assuming this is how you learn your coverage ended

You have a Medicare SELECT policy and move outside your plan's service area

If you have Original Medicare plus a Medicare SELECT policy and you move outside of your plan's service area, you have a full 123 days to buy Medigap Plan A, B, C, D, F, G, K, or L. The window opens 60 days before your SELECT coverage ends and closes 63 days later.

Talk to the insurance company that sold you your Medicare SELECT plan for more information about your options.

You joined an Advantage or Programs of All-inclusive Care for the Elderly (PACE) plan upon becoming eligible for Medicare Part A

If, during your first year of Medicare eligibility, you joined an MA or PACE plan and want to switch to Original Medicare within 12 months, you qualify for guaranteed issue under trial rights. Guidelines include:

• You may buy any Medigap policy offered by insurers in your state
• You may apply for a Supplement policy 60 days before your current coverage ends
• The window closes 63 days after you lose your current Medicare coverage

You left a Medigap policy to join an Advantage or SELECT plan and want to return to Original Medicare within 12 months

Dropping a Medigap policy to join your first Medicare Advantage or SELECT plan also qualifies as trial rights if you switch back within 12 months.

You have the right to buy the same Medigap policy you had before you made the switch, from the same insurance company (assuming they still sell it). If your former Supplement plan is not available, you can buy Medigap Plan A, B, C, D, F, G, K, or L that is sold by any insurance carrier in your state.

Your window to make these changes opens 60 days before your current Medicare coverage ends. It closes 63 days after your coverage end date.

You lose your current Medigap coverage through no fault of your own

You qualify for guaranteed issue rights if you lose your current Medicare Supplement plan because the insurance company goes bankrupt or for another reason that is not your fault. You have 63 days from the date you lose your current coverage to buy a new Medigap policy. Your options include Plans A, B, C, D, F, G, K, or L.

You leave a Medicare Advantage or Supplement plan because you were misled or the plan provider did not follow the rules

If your Medicare plan doesn't follow Medicare guidelines or misleads you in some way, you have the right to buy another Medigap plan. Options include Plans A, B, C, D, F, G, K, or L. And again, you have 63 days from the end of your current coverage to make the change.

What is Medicare SELECT?

Medicare SELECT is a type of Medigap policy that uses a provider network similar to what you find with an HMO health plan.

Before buying a Medicare SELECT policy, look carefully at the provider network. Unless it is a true emergency, any care you receive outside of this network will not be covered by the plan. There are usually other restrictions as well – ones you don't have with Original Medicare. For example, most Medicare SELECT plans require you to receive a referral from your primary doctor before they cover care received from a specialist.

Not all areas offer Medicare SELECT plans. If yours does, please note that the Medicare Supplement Open Enrollment Period applies, just as it does with standard Medigap plans.