Medicare Advantage and Medicare Supplement plans work completely differently. Medicare Advantage plans replace your Original Medicare, meaning you receive all Medicare benefits through one private insurance plan that includes Parts A, B, and usually D prescription coverage. These plans typically have networks of doctors and hospitals you must use, often feature low or zero monthly premiums, but include copays and deductibles when you receive care.

Medicare Supplement plans, also called Medigap, work alongside Original Medicare rather than replacing it. You keep your Original Medicare and the supplement plan helps pay the out-of-pocket costs like deductibles, coinsurance, and copays that Original Medicare doesn’t cover. With Medigap, you can see any doctor or specialist who accepts Medicare nationwide without network restrictions. These plans have higher monthly premiums but provide more predictable healthcare costs since they cover most or all of your Medicare cost-sharing.