A Guide to Supplemental Medicare Insurance

Learn about supplemental Medicare insurance (Medigap), its benefits, and how it helps cover healthcare costs not included in traditional Medicare.

What Is Supplemental Medicare Insurance?

As you plan for retirement, you’ll need to start learning about Medicare, the Federal health insurance program for people age 65 or older (and younger people with disabilities). This government-managed program, commonly referred to as “Original Medicare” is a fee-for-service health insurance program that consists of two parts: Medicare Part A (Hospital Insurance) and Medicare Part B (Medical Insurance). While Parts A and B provide a foundation for hospital and medical expenses, they don’t cover everything. 

Supplemental Medicare insurance, often called Medigap, is designed to help cover the “gaps” left by Medicare Parts A and B, Offered by private insurance companies, Medigap plans provide additional coverage for costs such as copayments, coinsurance, and deductibles that would otherwise come out of your pocket. These policies can help provide peace of mind by controlling and reducing  yourout-of-pocket healthcare costs to make retirement more financially manageable and enjoyable.

How Does Medigap Work?

Medigap supplements Medicare Parts A and B, providing additional coverage for expenses that Original Medicare doesn’t fully cover. While Medicare covers a large portion of your hospital and doctor visits, there are several costs — like deductibles and coinsurance — that you are still responsible for. Medigap policies help cover and limit these kinds of expenses, ensuring you aren’t left with astronomic medical debt as you age.

For example, if you have a hospital stay, Medicare Part A will cover most of the costs, but you’ll still be responsible for deductibles and copayments after a certain period. A Medigap plan can help cover these remaining costs. Similarly, Medicare Part B covers doctor visits, but you might have to pay 20% of the cost. Medigap helps by picking up where Medicare leaves off, covering things like:

  • Copayments for doctor visits or hospital stays;
  • Coinsurance for Medicare Part B services;
  • Deductibles for Medicare Part A and Part B;
  • Some emergency care when traveling internationally.


Medigap policies only work with Original Medicare, so Medigap is not an option if you have a Medicare Advantage plan (Part C). Medigap policies are also standardized across most states, meaning the coverage is generally the same regardless of the provider, though premiums can vary.

Types of Medicare Supplement Plans

There are several Medigap plans to choose from, each offering different levels of coverage. The plans are labeled with letters (A through N), and here’s a breakdown of how they differ:

  • Plan A: Covers basic benefits, including hospital coinsurance and additional hospital costs up to a year after Medicare benefits run out.
  • Plan B: Includes everything in Plan A, plus coverage for the Medicare Part A deductible.
  • Plan C: Covers Medicare Part A and B deductibles, coinsurance, and copayments but is no longer available to new Medicare enrollees as of 2020.
  • Plan D: Covers Medicare Part A deductibles and other cost-sharing, but not the Medicare Part B deductible.
  • Plan F: As the most comprehensive plan, it covers all out-of-pocket costs for Medicare-approved services. However, like plan C, it was only available to eligible enrollees before 2020.
  • Plan G: Similar to Plan F, but does not cover the Medicare Part B deductible. It is the most comprehensive option for new enrollees.
  • Plan K: Offers lower premiums but covers only 50% of most out-of-pocket costs, with an annual out-of-pocket limit.
  • Plan L: Covers 75% of most out-of-pocket costs and has an out-of-pocket limit.
  • Plan M: Covers half of the Medicare Part A deductible but none of the Part B deductible.
  • Plan N: Similar to Plan G, but requires copayments for doctor and emergency room visits.


Each plan is standardized, so no matter which insurance company you buy from, the primary benefits of each plan remain the same. However, premiums and added features may vary by provider.

How To Choose the Right Medigap Plan

Selecting the right Medigap plan depends on your financial situation, health conditions, and the type of medical services you expect to need. Here are some key considerations to guide your decision:

  1. Your health needs: If you anticipate needing frequent medical services, a more comprehensive plan like Plan G may be beneficial, covering a wide range of out-of-pocket costs.
  2. Your budget: Medigap plans vary in cost, and you’ll need to weigh the monthly premium against the level of coverage. Plans like K and L have lower premiums but higher out-of-pocket limits.
  3. Future medical costs: Consider what healthcare expenses you may face as you age. For instance, a plan with robust inpatient and outpatient coverage is a good choice if you’re concerned about hospital stays or frequent doctor visits.
  4. Eligibility: Some plans like Plan C and F are no longer available, so review your options accordingly.


Choosing the right Medigap plan requires careful consideration of your current and future healthcare needs and budget. By understanding the differences in each plan and weighing your options, you can find a policy that ensures financial peace of mind during your retirement. 

Medigap vs. Other Types of Health Insurance for Retirees

When planning for retirement, evaluate your health insurance options to ensure you get coverage that fits your needs. Medigap is just one of several insurance options available to retirees. 

Medigap vs. Medicare Advantage (Part C)

While Medigap supplements Medicare Parts A and B, Medicare Advantage (Part C) replaces it. Medicare Advantage plans are an all-in-one alternative to Original Medicare, offering bundled plans through private insurance companies that cover hospital, medical, and often prescription drug costs. Here are the key differences:

  • Coverage: Medigap only works with Original Medicare and helps cover out-of-pocket costs like copayments, coinsurance, and deductibles. Medicare Advantage plans provide an all-in-one package that may include everything from hospital and medical insurance to extras like dental, vision, and hearing.
  • Flexibility: Medigap allows you to visit any doctor or hospital that accepts Medicare. On the other hand, Medicare Advantage plans only enable you to visit a provider within a specific network, limiting your options.
  • Costs: Medigap plans usually have higher monthly premiums but lower out-of-pocket costs. Medicare Advantage plans often come with lower premiums but may include higher copayments or coinsurance when accessing services.
  • Extras: Medicare Advantage plans often offer additional benefits, such as coverage for prescription drugs (Part D), fitness programs, and wellness services, which Medigap does not .


Your choice between Medigap and Medicare Advantage depends on your healthcare needs and financial situation. Medicare Advantage may be a better option if you prefer lower upfront costs and don’t mind staying within a network of providers. However, if flexibility and comprehensive coverage are more critical, Medigap might be the right choice.

Medigap vs. Employer-Sponsored Retiree Plans

For retirees with access to an employer-sponsored plan, these plans often act as supplemental coverage to Medicare. While they help with out-of-pocket costs like Medigap, the coverage and costs of employer-sponsored plans can vary.

Employer plans may come with lower premiums, as the company often subsidizes them, whereas the policyholder pays Medigap premiums entirely. However, Medigap plans are standardized, meaning that the benefits are consistent across insurers, while employer-sponsored plans can differ depending on the company.

Prescription drug coverage is another factor to consider. Many employer-sponsored retiree plans include prescription drug benefits, whereas Medigap does not, requiring you to purchase a separate Medicare Part D plan.

Medigap vs. Medicaid

While Medigap is designed to help cover costs not covered by Medicare, Medicaid is a federal and state program that offers comprehensive health coverage to those with limited income and includes benefits not covered by Medicare, like long-term care. Here are the main differences between Medigap and Medicaid:

  • Eligibility: Medigap is available to anyone enrolled in Medicare, while Medicaid has strict income and asset limits. 
  • Cost: Medicaid typically costs little to no money for the beneficiary, as it is designed to cover healthcare expenses for those who cannot afford them. Conversely, Medigap requires monthly premiums, and costs vary based on the plan and location.
  • Coverage: Medicaid offers more comprehensive coverage, including services not typically covered by Medicare or Medigap, such as long-term nursing home care and prescription drugs. Medigap primarily helps cover out-of-pocket costs like deductibles and copayments for Medicare-covered services.
  • Coordination with Medicare: If you qualify for both Medicare and Medicaid (“dual-eligible”), Medicaid can act as a secondary payer to cover costs that Medicare doesn’t. In this case, a Medigap plan may not be necessary, as Medicaid would fulfill the role that Medigap typically plays.


Medigap is ideal for retirees with Medicare who want to cover out-of-pocket costs. Still, if you are eligible for Medicaid, it may provide more comprehensive coverage at a lower cost.

Benefits of Supplemental Medicare Insurance

Supplemental Medicare insurance makes healthcare more accessible and affordable. One of the most significant benefits is broader access to healthcare providers. Medigap works alongside Original Medicare, allowing you to choose your preferred healthcare providers without being restricted to a network.

Medigap also significantly reduces out-of-pocket costs. It covers expenses like copayments, coinsurance, and deductibles that Medicare doesn’t pay, which can otherwise accumulate quickly. By addressing these gaps, Medigap creates more predictable healthcare expenses, making it easier for retirees to budget and manage their medical costs effectively.

In addition, Medigap offers robust financial protection. Retirees may face overwhelming medical bills that lead to debt without supplemental coverage. By covering many costs that Medicare doesn’t, Medigap helps shield you from unexpected financial burdens and reduces the risk of accruing medical debt, ensuring a more secure retirement.

How To Enroll in a Medigap Plan

Enrolling in a Medigap plan is straightforward, but timing is crucial. The best time to enroll is during your Medigap Open Enrollment Period, which starts when you turn 65, and you’ve already enrolled in Medicare Part B. For six months, you have the right to purchase a Medigap policy provided in your state, and you won’t have to worry about not receiving coverage or higher premiums due to pre-existing conditions.

Here are the steps to enroll in a Medigap plan*:

  1. Review your Medicare coverage: Make sure you are enrolled in Medicare Part A and B, as Medigap works alongside these.
  2. Compare plans: Research the available Medigap plans in your area to find the one that best fits your healthcare needs and budget.
  3. Contact private insurance companies: Medigap plans are sold by private insurers. Contact them for quotes and compare their offerings.
  4. Complete the application: Once you have chosen a plan, submit an application to the insurance company. Be sure to enroll during your open enrollment period to avoid restrictions or higher premiums.
  5. Confirm your coverage: Once approved, you will receive documentation outlining your Medigap benefits and coverage details.


We strongly recommend working with a professional advisor who is licensed to sell Medicare plans in your state. Together, you’ll be able to sit down and go through your prescriptions, list of doctors, budget, unique health needs, lifestyle and more to find the best fit for you.

Outside of open enrollment, you may still be able to enroll in a Medigap plan under certain circumstances, such as losing other healthcare coverage. Check with your state’s insurance department or a licensed agent for specific details regarding eligibility outside the open enrollment period.

By reducing out-of-pocket expenses and offering financial protection, Medigap can help ensure you enjoy your retirement without overwhelming medical bills.

FAQs About Supplemental Medicare Insurance

Supplemental Medicare insurance, or Medigap, is a private insurance policy designed to cover gaps in traditional Medicare, such as copayments, coinsurance, and deductibles.

Medigap supplements Medicare Parts A and B by covering additional out-of-pocket expenses. At the same time, Medicare Advantage (Part C) replaces traditional Medicare and offers bundled coverage that may include prescription drugs, vision, and dental.

You can enroll in a Medigap plan the same month you turn 65 and after enrolling in Medicare Part B. For six months, insurers cannot deny coverage based on health conditions.

You can switch Medigap plans anytime, but you may be subject to medical underwriting. This means insurers can charge higher premiums or deny coverage based on your health status unless you qualify for a special enrollment period.

No, Medigap plans do not cover prescription drugs. You must enroll in a separate Medicare Part D plan for prescription drug coverage.

While most states standardize the benefits of Medigap plans, premiums, and coverage options can vary between insurance companies, so it’s essential to compare plans carefully.

Medigap does not cover long-term care, vision, dental, hearing aids, eyeglasses, or private-duty nursing. It also does not cover prescription drugs or care outside the U.S. unless specified by the plan.

The cost of Medigap varies depending on factors like your age, location, and the specific plan you choose. Premiums can range from around $50 to over $300 per month.

No, you cannot have both Medigap and Medicare Advantage plans. If you switch to Medicare Advantage, you must drop your Medigap policy.

Medigap covers many out-of-pocket costs, such as copayments and deductibles, but it does not cover everything. You will still need to follow Medicare’s guidelines for services that are and aren’t covered.

Start Planning Today for a Secure and Healthy Retirement

For more information about Medigap, Medicare, and other retirement planning resources, visit My Guide To Retirement and explore how to make informed decisions about your healthcare and financial future.