Navigating the Medicare Maze: Understanding the Incompatibility of Medigap and Medicare Advantage Plans

As you embark on the journey of Medicare coverage, understanding the intricacies of the various plans and their compatibility is crucial. One of the most common questions that arise is whether you can enroll in both a Medigap (Medicare Supplement Insurance) plan and a Medicare Advantage plan simultaneously. The answer is a resounding “no” – these two types of plans are mutually exclusive, and you cannot have both at the same time.

What is a Medigap Plan?

A Medigap plan, also known as Medicare Supplement Insurance, is a private insurance policy designed to fill the “gaps” in coverage left by Original Medicare (Parts A and B). These gaps can include deductibles, copayments, and coinsurance costs that beneficiaries would otherwise have to pay out-of-pocket.

Medigap plans are standardized by the federal government and are offered by private insurance companies. They are identified by letters (A, B, C, D, F, G, K, L, M, and N), with each plan offering a different set of benefits and coverage levels.

What is a Medicare Advantage Plan?

Medicare Advantage plans, also known as Part C, are an alternative way to receive your Medicare benefits. These plans are offered by private insurance companies that have been approved by Medicare. They provide all the coverage of Original Medicare (Parts A and B), and most plans also include additional benefits such as prescription drug coverage, vision, dental, and hearing services.

Medicare Advantage plans may come in the form of Health Maintenance Organizations (HMOs), Preferred Provider Organizations (PPOs), Private Fee-for-Service (PFFS) plans, or Special Needs Plans (SNPs) designed for beneficiaries with specific health conditions.

The Incompatibility of Medigap and Medicare Advantage Plans

The reason you cannot have a Medigap plan and a Medicare Advantage plan at the same time is that they are fundamentally different in how they work and what they cover. Here’s why they are incompatible:

  1. Coverage Duplication: Medigap plans are designed to work alongside Original Medicare, covering the out-of-pocket costs that Medicare doesn’t cover. Medicare Advantage plans, on the other hand, are an alternative to Original Medicare and provide all the coverage of Parts A and B within a single plan. Having both would result in duplicated coverage and unnecessary costs.

  2. Billing Complications: Medigap plans are specifically designed to coordinate with Original Medicare’s billing process. If you have a Medicare Advantage plan, there is no need for a Medigap policy, as the Medicare Advantage plan handles all claims and billing directly.

  3. Legal Restrictions: It is illegal for insurance companies to sell you a Medigap policy if you already have a Medicare Advantage plan. The Centers for Medicare & Medicaid Services (CMS) prohibits this practice to prevent beneficiaries from paying for overlapping coverage.

Making the Choice: Medigap or Medicare Advantage?

When you become eligible for Medicare, you will need to decide whether to enroll in Original Medicare (Parts A and B) and potentially purchase a Medigap plan, or opt for a Medicare Advantage plan instead. Here are some factors to consider:

  • Out-of-Pocket Costs: Medigap plans can help reduce your out-of-pocket costs for deductibles, copayments, and coinsurance, but you’ll need to pay the monthly Medigap premium in addition to your Part B premium. Medicare Advantage plans often have lower out-of-pocket costs but may also have higher monthly premiums.

  • Provider Network: Medicare Advantage plans typically have a network of preferred providers, while Original Medicare and Medigap plans allow you to see any doctor or hospital that accepts Medicare patients.

  • Additional Benefits: Many Medicare Advantage plans offer additional benefits like prescription drug coverage, vision, dental, and hearing services, which are not covered by Original Medicare or Medigap plans.

  • Travel and Portability: If you plan to travel frequently or live in multiple locations, Original Medicare and Medigap plans may be more convenient, as they provide coverage nationwide.

Making the Switch

If you initially enroll in a Medicare Advantage plan but later decide that a Medigap plan would better suit your needs, you can switch back to Original Medicare during certain enrollment periods. However, keep in mind that you may face underwriting requirements or be denied coverage for pre-existing conditions if you try to purchase a Medigap policy outside of your initial Medigap Open Enrollment Period.


Understanding the differences and limitations between Medigap plans and Medicare Advantage plans is crucial for making an informed decision about your Medicare coverage. While you cannot have both types of plans simultaneously, each option offers its own advantages and disadvantages. Carefully evaluate your individual needs, preferences, and budget to determine which plan is the best fit for you.

If you find yourself in need of guidance or have questions about navigating the Medicare landscape, don’t hesitate to seek assistance from a licensed insurance agent or a trusted Medicare counselor. Making the right choice can ensure you have the comprehensive coverage you need for a secure and comfortable retirement.

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Can you have 2 Medicare plans at the same time?

You can’t have a Medicare Advantage plan and a Medicare Supplement insurance plan at the same time. That means if you’re interested in these types of Medicare coverage, you’ll need to choose between the two. Here’s some information about them that might help you decide. Compare 2024 Medicare Advantage plans.

Can you have Medigap and private insurance at the same time?

It is possible to have both private insurance and Medicare at the same time. When you have both, a process called “coordination of benefits” determines which insurance provider pays first. This provider is called the primary payer.

Can you have Medicare Part B and employer insurance at the same time?

Can I combine employer health insurance with Medicare? If you or your spouse are working and covered through an employer, you can also decide to keep this coverage and enroll in Original Medicare, Part A and/or Part B to get additional health coverage.

Can you have Medicare Part C and D together?

Can you have both Medicare Part C and Part D? You can’t have both parts C and D. If you have a Medicare Advantage plan (Part C) that includes prescription drug coverage and you join a Medicare prescription drug plan (Part D), you’ll be unenrolled from Part C and sent back to original Medicare.

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