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Medicare supplemental insurance (also called Medigap) covers the out-of-pocket health care costs you may incur with Original Medicare (parts A and B). In most states, there are 10 standardized Medigap plans with letter names that are sold by private insurers, with premiums regulated by the states. What you pay in monthly premiums may depend on where you live, what coverage you get and how old you are. Medigap plans are not used with Medicare Advantage plans.
What Medigap plans cover
Part A and Part B coinsurance.
Part A and Part B copayments.
As well as:
What Medigap plans don’t cover
Medigap policies don’t cover:
Vision care (including eyeglasses).
Private duty nursing.
In addition to:
What you’ll pay
When to enroll in Medigap
Enrolling in Medicare Supplement Insurance can be tricky. You’ll pay more, or even be denied coverage, if you don’t follow the rules for enrollment carefully.
How Medigap works with other insurance
With Original Medicare: Medicare Supplement Insurance helps pay for out-of-pocket costs incurred with Original Medicare Parts A and B only.
With Medicare Advantage: Medicare Supplement Insurance doesn't work with Medicare Advantage plans. It is illegal to sell a Medigap plan to a Medicare Advantage beneficiary.
How to compare plans
Start by determining which of the various lettered plans will fit your health care needs. For a side-by-side comparison, see this page of Medicare.gov.
Once you choose the type of plan you want, you’ll need to compare prices among all the insurers that offer that plan in your area. Remember, prices can vary considerably but coverage is the same for each lettered plan. This tool on Medicare.gov can help you compare prices. Your State Health Insurance Assistance Program (SHIP) or your state insurance department can also help.
Nerd tip: Be sure to contact the insurer for each policy you are considering to double-check prices and coverage availability. Information available online can be out of date quickly.