How Medigap works
Original Medicare pays first. Your Medigap plan then pays its share of what is left. You pay a monthly premium to the insurer on top of your Part B premium.
Medigap plans are standardized by letter in most states. A Plan G from one company covers the same benefits as a Plan G from another. The price is what changes, so shopping companies is worth the effort.
Medigap does not include drug coverage. Most people with a Medigap plan also buy a stand-alone Part D plan.
Plan G vs. Plan N
These two plans get the most attention from new enrollees. Plan F covers a little more, but it is only open to people who were eligible for Medicare before January 1, 2020.
| Benefit | Plan G | Plan N |
|---|---|---|
| Part B deductible ($283 in 2026) | You pay it | You pay it |
| Part A hospital deductible | Covered | Covered |
| Part B 20% coinsurance | Covered | Covered, minus small copays |
| Office visit copay | None | Up to $20 |
| Emergency room copay | None | Up to $50 if not admitted |
| Part B excess charges | Covered | Not covered |
| Foreign travel emergency | 80% after deductible | 80% after deductible |
When to buy: the six-month window
Your best time to buy a Medigap plan is your Medigap Open Enrollment Period. It lasts six months and starts the first month you are 65 or older and enrolled in Part B.
During that window, a company cannot turn you down or charge more because of your health. After it closes, most states let insurers ask health questions and decline you. That is why the choice between Medigap and Medicare Advantage matters so much at 65. Read more in our side-by-side guide.
What Medigap costs
Premiums depend on your age, ZIP code, tobacco use, the plan letter and how the company prices its policies. Some companies price by your age at purchase, some by your current age, and some charge everyone the same rate. Ask which method a company uses, since it shapes how your premium grows over time.
A high-deductible version of Plan G is also sold. In 2026 you pay the first $2,950 of covered costs before it kicks in, in exchange for a lower premium.