If you’re approaching age 65 or already enrolled in Medicare, understanding the Medicare Supplement Open Enrollment Period is essential. Also known as Medigap Open Enrollment, this is your best opportunity to enroll in a Medigap policy that helps cover costs Original Medicare doesn’t—like copayments, coinsurance, deductibles, and even emergency care abroad.
While Original Medicare (Parts A and B) provides vital Medicare benefits, it doesn’t pay for everything. That’s where Medicare Supplement Insurance, also known as Medigap, comes in. Offered by private insurance companies and regulated under federal law, Medigap helps Medicare beneficiaries reduce out-of-pocket health care expenses.
In this guide, we’ll cover what Medigap is, how the open enrollment period works, and how to compare top plans like Medicare Supplement Plan G and Plan F.
What Is Medicare Supplement (Medigap)?
A Medicare Supplement policy, or Medigap, is a type of health insurance sold by private insurance companies that helps pay some of the costs not covered by Original Medicare. These policies are standardized and designed to work alongside your Medicare coverage.
What Medigap covers:
- Part A and B coinsurance and copayments
- Part A deductible
- Skilled nursing facility care coinsurance
- Foreign travel emergency care (in most plans)
- First 3 pints of blood
Medigap does not cover:
- Prescription drugs (you’ll need a separate Part D plan)
- Routine dental, vision, or hearing
Popular Medigap plans include:
- Plan F: Offers the most comprehensive benefits (only available to those eligible before 2020).
- Plan G: Offers similar coverage, minus the Medicare Part B deductible, and is now the most popular choice among new enrollees.
Medicare Supplement Open Enrollment Period
The Medigap Open Enrollment Period is a six-month window that begins the month you are both 65 or older and enrolled in Medicare Part B. During this open enrollment period, insurance companies must offer you any Medigap policy they sell, without:
- Medical underwriting
- Higher premiums due to pre-existing conditions
- Risk of being denied coverage
Open enrollment matters because you get guaranteed issue rights under federal law. You also avoid late enrollment penalties and get the best rates from your insurance company.
If you wait until after this window closes, you may lose your guaranteed rights and face medical underwriting, potential coverage denial, and higher monthly premiums.
Medicare Supplement Plan G vs. Plan F
Choosing between Plan G and Plan F is one of the most common decisions Medicare beneficiaries face when enrolling in a Medigap policy.
| Feature | Plan F | Plan G |
|---|---|---|
| Part A deductible | ✓ | ✓ |
| Part B deductible | ✓ | ✗ |
| Part B excess charges | ✓ | ✓ |
| Skilled nursing facility care | ✓ | ✓ |
| Foreign emergency care | ✓ | ✓ |
| Monthly premium | Higher | Lower (generally) |
Key Differences:
- Plan F covers everything Medicare doesn’t, including the Part B deductible. However, it’s only available to those who became Medicare-eligible before January 1, 2020.
- Plan G is the most comprehensive option for those newly eligible. It has slightly lower premiums and only requires you to pay the Part B deductible yourself.
Guaranteed Issue Medicare Supplement Plans
Guaranteed issue rights protect you from being denied a Medigap policy based on your health status. These rights are provided under federal law and apply during specific situations outside of your standard open enrollment period.
Plans available during Guaranteed Issue include A, B, C, F (only eligible before 2020), K, and L.
When Do Guaranteed Issue Rights Apply?
- You lose other health insurance coverage (e.g., employer or union plan)
- Your Medicare Advantage plan is discontinued, or you move out of its service area
- You drop your Medicare Advantage plan within the first 12 months of joining
Note: Some plans may not be available in your state or through every insurance company.
How to Change Your Medicare Supplement Plan
Many Medicare beneficiaries wonder how to change their supplemental plan. The answer depends on when and why you’re switching.
Steps to Change a Medigap Policy:
- Compare plans and pricing from different insurance companies
- Apply for a new Medigap policy
- If required, go through medical underwriting
- Once accepted, cancel your old policy
When You Can Switch Without Underwriting:
- During your Medigap Open Enrollment Period
- If you qualify for a guaranteed issue right
Tips for Switching:
- Don’t cancel your current Medigap policy until you’re approved for the new one
- Work with a licensed advisor to compare benefits and avoid coverage gaps
- Watch out for late enrollment penalties if switching to other types of Medicare coverage, like Part D
Medicare Supplement Eligibility Requirements
To qualify for a Medicare Supplement plan, you must be 65 years old or older and be enrolled in Medicare Part B
If you’re under 65 and have disability-based Medicare, availability varies by state. Some states require insurance companies to offer at least one Medigap policy to people under 65, though premiums may be higher. State-specific rules also affect enrollment windows, plan availability, and health insurance rights
Final Thoughts
Enrolling in a Medicare Supplement plan during your open enrollment period is the best way to lock in comprehensive Medicare coverage at the most affordable rates, without worrying about medical underwriting or late enrollment penalties. Whether you’re comparing Plan G vs. Plan F, exploring your guaranteed issue rights, or just wondering how to switch plans, understanding your options can protect both your health and your finances.
Because rules vary by state and situation, working with a licensed Medicare insurance advisor can help you make the best decision. They can walk you through your Medicare benefits, compare plans across insurance companies, and help you find the policy that’s right for your needs.
Want help choosing the right Medigap policy? Visit MedicareSchool.com to watch our online Medicare educational workshop, speak with a licensed expert about your health insurance options, and get personalized help comparing Medicare Supplement policies based on your needs and location.
Stop stressing about Medicare—get the coverage and peace of mind you deserve.
FAQs About Medicare Supplement Plans
Can I switch Medigap plans at any time?
Technically, yes—you can apply to switch your Medigap policy at any time. However, unless you’re within your Medicare Supplement Open Enrollment Period or qualify for a guaranteed issue right, your application may be subject to medical underwriting. This means an insurance company can:
- Deny your application
- Charge a higher premium based on your health history
- Impose waiting periods for pre-existing conditions.
To avoid these risks, most Medicare beneficiaries should try to make changes during open enrollment or in qualifying special circumstances.
What is the difference between Medicare Supplement Plan G and Plan F?
Both plans offer comprehensive Medicare coverage, but there are a few key differences:
- Plan F: Covers all out-of-pocket costs, including the Medicare Part B deductible. It’s no longer available to people who became eligible for Medicare benefits on or after January 1, 2020.
- Plan G: Covers everything Plan F does except the Part B deductible. It typically has lower monthly premiums, making it a cost-effective option for new enrollees.
If you’re eligible for both, compare your projected healthcare expenses and monthly health insurance premiums to decide which plan offers better long-term value.
Are Medicare Supplement plans standardized in every state?
Yes, under federal law, Medigap policies are standardized in most states. This means a Plan G from one insurance company offers the same core benefits as Plan G from another provider. However, plan costs and customer service can vary.
Exceptions:
- Massachusetts, Minnesota, and Wisconsin standardize their Medigap plans differently, offering unique plan structures under state-specific rules.
Do Medicare Supplement plans cover prescription drugs?
No. Medigap policies do not include prescription drug coverage. If you want drug coverage, you’ll need to enroll in a separate Medicare Part D plan. It’s important to do this during your initial enrollment period or risk late enrollment penalties.
If you need all-in-one coverage, you may want to consider a Medicare Advantage plan instead. Medicare Advantage plans may offer additional benefits that are not included in Original Medicare. Benefits vary by plan and location, and limitations may apply. Contact a licensed agent to learn more. However, Advantage plans differ from Medigap plans and cannot be used together.
What happens if I miss my Medicare Supplement Open Enrollment Period?
If you miss your Medigap Open Enrollment Period, you can still apply for a policy at any time, but you may face challenges, including:
- Medical underwriting
- Higher health insurance premiums
- Possible denial of coverage
Outside the open enrollment period, your ability to get a Medicare Supplement plan with full guaranteed issue rights is generally limited to specific qualifying events, like losing employer coverage or moving out of your plan’s service area.
To minimize your costs and maximize coverage, enroll during your initial six-month Medigap open enrollment window.
What are guaranteed issue rights, and when do they apply?
Guaranteed issue rights are protections under federal Medicare law that ensure you can buy a Medigap policy without:
- Medical underwriting
- Higher premiums due to health history
- Being denied by an insurance company
These rights apply during:
- Your Medicare Supplement Open Enrollment Period
- Specific life events, like losing group health insurance, moving out of a Medicare Advantage plan’s service area, or dropping a Medicare Advantage plan within the first 12 months of enrollment
During these times, you can enroll in select standardized Medigap plans, often including Plan A, Plan B, Plan C, Plan F, Plan K, and Plan L, depending on your state and eligibility.
Can I have both a Medicare Advantage plan and a Medigap policy?
No. It is illegal to be enrolled in both a Medicare Advantage plan and a Medicare Supplement plan at the same time. These two types of health insurance serve different purposes:
- Medigap policies supplement Original Medicare (Parts A and B) by covering out-of-pocket expenses.
- Medicare Advantage plans (Part C) are alternatives to Original Medicare and typically operate within provider networks, except for urgently or emergently needed care.
If you’re switching from Medicare Advantage to Original Medicare, wait until your disenrollment is processed before applying for a Medigap plan.
How do I compare Medigap plans from different insurance companies?
While the benefits are standardized, insurance companies set their own monthly premiums, underwriting criteria, and service levels. To compare plans:
- Use Medicare.gov or work with an independent licensed, MedicareSchool.com advisor.
- Compare premiums, rate increase history, financial stability of the insurer, and customer service ratings.
- Check if the insurance company offers household discounts or other incentives that can lower your overall cost.