What is Medigap (Medicare Supplement)?
Medigap, also called Medicare Supplement insurance, is a private policy that helps pay some of the out-of-pocket costs Original Medicare (Parts A and B) leaves you to cover — such as deductibles, copayments, and coinsurance. It works alongside Original Medicare, not instead of it: Medicare pays its share first, and your Medigap policy helps with some of what's left.
How Medigap works
Medigap plans are standardized and labeled with letters (for example, Plan G or Plan N), so a Plan G from one company covers the same benefits as a Plan G from another — the main differences are price and the company's service. Medigap policies let you see any provider in the country that accepts Medicare, with no networks. They do not include prescription drug coverage, so people with Medigap usually add a standalone Part D plan.
What to know before you buy
The best time to buy is usually during your Medigap Open Enrollment Period — the six months that begin when you are 65 or older and enrolled in Part B — because during that window you generally cannot be turned down or charged more for health reasons. Outside that window, the rules vary by state. Medigap does not work with Medicare Advantage; you have one or the other. For your full options, contact Medicare.gov, 1-800-MEDICARE, or your State Health Insurance Assistance Program (SHIP).
Frequently asked questions
Does Medigap cover prescriptions?
No. Medigap policies sold today do not include drug coverage. If you want help with prescription costs, you typically add a standalone Medicare Part D plan.
Can I use any doctor with Medigap?
Generally yes — Medigap works with Original Medicare, so you can see any provider in the U.S. that accepts Medicare, without networks or referrals.
Is Medigap the same as Medicare Advantage?
No. Medigap supplements Original Medicare and has no networks; Medicare Advantage is a different path that provides your Part A and B benefits through a private plan, usually with a network. You cannot have both at once.
This is general education, not personalized advice, and plan details change every year. For all of your options, contact Medicare.gov, 1-800-MEDICARE, or your local State Health Insurance Assistance Program (SHIP) at shiphelp.org.