What is Medigap insurance?

Even though Medicare covers the bulk of your medical expenses after you turn 65, you’ll still find gaps in its coverage. A Medicare supplement policy, also called Medigap, can cover many of these expenses:

• Deductibles. Expect to pay a certain amount out of pocket every year before Medicare Part A and Part B coverage kicks in: In 2025, $1,676 for Part A if a patient is admitted to the hospital and $257 for Part B. But deductibles aren’t everything. You’ll still have to pay part of the costs for doctors’ services, long stays in a hospital or a skilled nursing facility, medical equipment, outpatient care and other services.
• Copayments. The set fee you pay for your health services, such as $25 for a doctor visit.
  
• Coinsurance. The percentage of a bill you must pay for a service or medical equipment, such as 20 percent for an outpatient procedure.

Medicare pays its share of the Medicare-approved amount for your health care expenses first. Then Medigap kicks in to help cover your portion of the costs.

Private insurance companies sell Medigap policies, but federal and state governments regulate them. You’ll pay premiums to the Medigap company you choose in addition to premiums you pay Medicare for Part A or Part B.

A big plus for Medigap is you can use any doctor or hospital that accepts Medicare, unlike private Medicare Advantage plans that usually have provider networks and charge more or don’t cover out-of-network providers.

What does a Medigap policy offer? 

Pays the coinsurance. All Medigap plans cover the 20 percent Part B coinsurance you otherwise would pay yourself for physician visits and other outpatient services. They also cover Part A coinsurance costs for inpatient hospital stays.

Medicare covers the first 60 days as an inpatient in a hospital, but you’re responsible for paying the coinsurance for days 61 to 90 — $419 in 2025 — and an $838 daily coinsurance after that for up to 60 lifetime reserve days in 2025.

Covers some deductibles. Most Medigap plans cover the Medicare Part A hospital deductible, which is $1,676 per benefit period in 2025.

Adds health benefits. Although Medicare won’t cover your hospital stay after you’ve depleted your lifetime reserve, all Medigap policies cover the daily coinsurance costs and up to 365 additional lifetime days in the hospital after your Medicare benefits are used up. All Medigap plans cover the first three pints of blood you may need each year, either in full or in part.

May cover other costs. Some plans pay coinsurance costs for skilled nursing facilities and hospice care; excess charges from doctors who don’t accept assignment, which means they can charge up to 15 percent more than the Medicare-approved amount; and foreign travel health care emergencies.

How will I know what plans offer the benefits I need?

Deciphering the series of letters that designate each plan will give you the answer. In 1992, the federal government standardized the types of Medigap plans insurers can offer nationwide.

Today you have 10 options by letter: A, B, C, D, F, G, K, L, M and N. Every plan with the same letter designation must include the same coverage; premiums can vary from company to company.