When to Get Medicare Supplemental Insurance Coverage

What Is Medicare Supplement (Medigap) Insurance?

Medicare Supplement Insurance, known as Medigap, is additional coverage offered by private insurers designed to help pay for out-of-pocket costs not covered by Original Medicare (Medicare Part A and Part B). These expenses typically include:

• Copayments
• Coinsurance
• Deductibles
• Some medical services not covered by Original Medicare (depending on the plan)

It’s important to note that Medigap policies only work in conjunction with Original Medicare-not with Medicare Advantage plans. If you have a Medigap policy, you cannot use it with a Medicare Advantage plan. For a detailed overview on policy features and plan types, see our comprehensive Medicare Supplement Plans resource.

The Best Time to Buy Medigap: Your 6-Month Open Enrollment Period

The Medigap Open Enrollment Period is widely considered the best time to get Medicare Supplement insurance.
During this 6-month window, starting the first day of the month you are both age 65 or older and enrolled in Medicare Part B, you access unique protections and eligibility rules.

• No medical underwriting: Insurers cannot decline your application or charge you higher rates due to your medical history or preexisting conditions.
• Guaranteed issue rights: You can enroll in any Medigap policy available in your state, regardless of health status.
• One-time opportunity: This is usually a one-time period for most people; once it ends, guaranteed access may not be available.

Example:
If your 65th birthday is in October but you delay Medicare Part B because of employer coverage and instead enroll in January, your 6-month Medigap window will be January 1 to June 30. The timing aligns with your Part B effective date, not your birthday.

To understand how this open enrollment window works in the context of changing coverage or shopping for new plans, visit our Free Look Period for Medicare Supplement Policies Explained for details.

What Happens If You Miss the Open Enrollment Period?

Missing your Medigap Open Enrollment Period does not mean you cannot buy a policy. However, there are significant risks and potential obstacles if you wait:

• Medical underwriting applies: Insurers may require health questions and deny coverage based on your medical history.
• Higher premiums: You may be charged more for the same plan because of health issues or age.
• Waiting periods for preexisting conditions: Coverage for existing health conditions may be delayed (usually up to six months).
• Limited plan selection: Insurers can decide which plans they offer after the open enrollment window closes.

While certain guaranteed issue rights may apply (see next section), these are typically tied to special circumstances.

Other Times You Can Buy Medigap with Guaranteed Rights

Outside the standard open enrollment, you may qualify for guaranteed issue rights in specific situations:

• Your Medicare Advantage plan withdraws from your area or shuts down
• Your current Medigap insurer goes bankrupt or ceases to offer coverage
• You lose employer or union retiree coverage that helped pay Medicare costs
• You move outside your Medicare SELECT policy’s service area
• You drop a Medicare Advantage or PACE plan within the first year (trial rights)

Most of these situations grant a 63-day window (sometimes up to 90 days) from the loss of coverage or triggering event to exercise your right to buy certain Medigap plans without medical underwriting. Act promptly, as missing this limited-enrollment window may result in denial or higher costs.

For more context on how these special rules intersect with other types of Medicare coverage, see our article on What Part of Medicare Covers Durable Medical Equipment?

Common Misconceptions About Medigap Enrollment

Misconception #1: “I can only change Medigap coverage during the Medicare Annual Open Enrollment.”

Truth: You can apply for Medigap at any time of the year. However, outside of your 6-month open enrollment or a guaranteed issue window, medical underwriting applies, and you could be denied or pay more.

Misconception #2: “Medigap covers medications.”

Truth: Medigap doesn’t cover prescription drugs. For prescription benefits, you’ll need a separate Medicare Part D plan. See Medicare Billing Guide 2025: Updates and Compliance for information about payment and drug coverage.

Misconception #3: “My Medigap policy covers my spouse.”

Truth: Medigap covers only the policyholder. Each person must get their own policy.

Misconception #4: “If I apply after open enrollment, they have to accept me.”

Truth: After your open enrollment period, insurers can deny or charge more unless you have a guaranteed issue right.

How to Make the Most of Your Medigap Enrollment Window

• Know your key dates: Mark the date you turn 65 and the date your Part B begins. Your open enrollment period is based on these.
• Compare plan types: Different Medigap plans offer different benefits (Plan G, N, etc.). Compare based on your needs and future health risks.
• Get premium quotes: Prices differ between insurers, even for identical coverage. Investigate how each company rates its policies (community-rated, issue-age-rated, attained-age-rated).
• Plan ahead for the future: Look at plans that fit your travel habits or anticipated medical needs.

If you’d like more information or tools to compare Medigap options, start at our How to Get Medicare hub.

Frequently Asked Questions

• Can I get Medigap if I’m under 65 and on Medicare for disability?
  Some states provide a Medigap enrollment window for those under 65 on disability. Availability, eligibility, and pricing depend on your state’s rules-contact your state insurance department or visit Medicare Supplement Plans for more guidance.
• Can I change Medigap plans after my initial enrollment?
  You can apply to switch plans any time, but after your open enrollment ends, underwriting will usually apply unless you qualify for a guaranteed issue situation.
• Do I need Medigap with a Medicare Advantage plan?
  No, you can’t have Medigap and Medicare Advantage together. Medigap only works with Original Medicare. For more on Medicare plan coordination, you may want to read about the Medicare Billing Guide 2025.
• Will my doctor accept my Medigap plan?
  As long as your doctor participates in Medicare, your Medigap policy is accepted. Medigap doesn’t use provider networks like Medicare Advantage.

Next Steps: When to Act

1. If you are turning 65 or enrolling in Part B soon:
   • Verify your Medicare Part B effective date.
   • Mark your 6-month Medigap Open Enrollment Period window on your calendar.
   • Start shopping and comparing plans before your enrollment period begins.
2. If your open enrollment period has passed:
   • Check for guaranteed issue events (such as lost employer coverage, moving, or changes in Medicare Advantage).
   • If you don’t qualify, prepare for medical underwriting and possible premium increases during the application process.
3. If you need assistance navigating Medicare:
   • Contact your State Health Insurance Assistance Program (SHIP) for free, unbiased help.
   • Consult a licensed Medicare insurance agent for plan comparisons and personalized advice.

Still have questions or want a more detailed look at how to enroll? Use our How to Get Medicare resource for step-by-step instructions and additional support.