What Is Medigap (Medicare Supplement Insurance)?
Medigap (Medicare Supplement Insurance) — also called Medicare Supplement Insurance, Medigap
Medigap, also called Medicare Supplement Insurance, is private health insurance that helps pay some of the out-of-pocket costs not covered by Original Medicare, such as certain deductibles, copayments, and coinsurance.
Official source: medicare.gov
Medigap, also called Medicare Supplement Insurance, is private health insurance that helps pay some of the out-of-pocket costs not covered by Original Medicare, such as certain deductibles, copayments, and coinsurance. Medigap policies work alongside Original Medicare—they do not replace it—and are sold by private insurance companies regulated under federal and state law.
What is Medigap?
Original Medicare pays a significant portion of covered healthcare costs, but beneficiaries are still responsible for certain deductibles, copayments, coinsurance, and other expenses.
A Medigap policy helps cover some of those remaining costs.
To purchase a Medigap policy, you generally must be enrolled in:
- Medicare Part A (Hospital Insurance)
- Medicare Part B (Medical Insurance)
Medigap policies are standardized under federal law in most states, meaning plans with the same letter generally provide the same basic benefits regardless of the insurance company that sells them.
How does Medigap work?
Medigap works together with Original Medicare.
Here's how the process typically works:
- You receive care from a provider that accepts Medicare.
- Original Medicare pays its share of the approved amount.
- Your Medigap policy pays some or all of the remaining covered costs according to your specific plan.
You continue paying your Medicare Part B premium and the premium for your Medigap policy.
What does Medigap cover?
Coverage depends on the specific Medigap plan you purchase.
Depending on the plan, Medigap may help pay for:
- Medicare Part A coinsurance
- Medicare Part B coinsurance or copayments
- Blood transfusion costs (first three pints)
- Skilled nursing facility coinsurance
- Hospice care coinsurance
- Foreign travel emergency care (certain plans)
- Other Medicare-approved cost sharing
Not every Medigap plan covers every expense.
Benefits are standardized by plan letter in most states.
What doesn't Medigap cover?
Most Medigap policies do not cover:
- Prescription drugs (Medicare Part D provides this coverage)
- Long-term care
- Routine dental care
- Routine vision care
- Hearing aids
- Private-duty nursing
Many beneficiaries purchase separate coverage for these services if needed.
Medigap vs. Medicare Advantage
These two types of coverage are frequently confused.
Medigap
- Works alongside Original Medicare.
- Helps pay certain out-of-pocket Medicare costs.
- Generally allows beneficiaries to see any provider nationwide who accepts Medicare.
- Does not replace Medicare.
- Replaces Original Medicare as the way Medicare benefits are delivered.
- Administered by private insurance companies.
- Often includes additional benefits such as dental, vision, hearing, or prescription drug coverage.
- Usually uses provider networks.
In most cases, you cannot use a Medigap policy with a Medicare Advantage plan.
When should you enroll in Medigap?
For many people, the best time to buy a Medigap policy is during the Medigap Open Enrollment Period.
This six-month enrollment window generally begins when:
- You are age 65 or older, and
- You are enrolled in Medicare Part B.
During this period, insurance companies generally cannot deny you coverage or charge higher premiums because of your health based on federal Medigap protections, though certain state laws may provide additional rights.
After this enrollment period ends, medical underwriting may apply in many states unless you qualify for guaranteed issue rights.
How much does Medigap cost?
Premiums vary based on several factors, including:
- Your age
- Where you live
- The insurance company
- The Medigap plan you select
- The insurer's pricing method
Even though benefits are standardized for plans with the same letter in most states, monthly premiums may differ significantly between insurance companies.
Why this matters
Original Medicare does not include an annual out-of-pocket maximum for Part A and Part B services. For beneficiaries who expect ongoing medical care or want greater predictability in healthcare costs, a Medigap policy may significantly reduce out-of-pocket expenses.
Choosing between Original Medicare with Medigap and Medicare Advantage is one of the most important Medicare decisions beneficiaries make.
In real life
- A retiree enrolled in Original Medicare purchases a Medigap Plan G policy to reduce exposure to Medicare deductibles and coinsurance.
- A beneficiary who frequently travels throughout the United States chooses Original Medicare with Medigap because they want broad access to providers that accept Medicare.
- A couple compares monthly Medigap premiums from several insurance companies because standardized benefits are generally the same for plans with the same letter.
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Frequently asked questions about Medigap (Medicare Supplement Insurance)
What is Medigap?+
Medigap is private insurance that helps pay certain out-of-pocket healthcare costs not covered by Original Medicare, including some deductibles, copayments, and coinsurance.
Is Medigap the same as Medicare Advantage?+
No. Medigap supplements Original Medicare. Medicare Advantage is an alternative way to receive Medicare benefits through a private insurance company.
Can I have both Medigap and Medicare Advantage?+
Generally, no. Medigap policies are designed to work only with Original Medicare and generally cannot be used to pay Medicare Advantage plan costs.
Does Medigap cover prescription drugs?+
No. Medigap policies sold today generally do not include prescription drug coverage. Beneficiaries who want drug coverage typically enroll in a separate Medicare Part D plan.
Are all Medigap plans the same?+
Benefits are standardized by plan letter in most states, meaning a Plan G from one insurance company generally offers the same basic benefits as a Plan G from another company. However, premiums and customer service may differ.
When is the best time to buy a Medigap policy?+
For many people, the best time is during the six-month Medigap Open Enrollment Period that generally begins when they are both age 65 or older and enrolled in Medicare Part B.
Sources
- Medigap (Medicare Supplement Insurance)
Medicare.gov — medicare.gov - Medigap Basics
Medicare.gov — medicare.gov - Medigap
Centers for Medicare & Medicaid Services — cms.gov - Consumer Insurance Resources
National Association of Insurance Commissioners — content.naic.org - Medicare Costs
Medicare.gov — medicare.gov