Medicare Parts A, B, C and D: what each part covers

A plain-English overview of the four parts of Medicare, what each covers, what they cost in 2026, and how Medigap fits in.

Medicare has four "parts", named with letters. Two are run by the federal government (A and B), and two are offered by private insurers approved by Medicare (C and D). Medigap is a fifth piece that is not a "part" at all.

Part A: hospital insurance

Covers inpatient hospital stays, skilled nursing after a hospital stay, hospice, and some home health care. Most people pay no premium. You pay a $1,736 deductible per benefit period in 2026.

Part B: medical insurance

Covers doctor visits, outpatient care, preventive services, lab tests, imaging, durable medical equipment and many drugs given in a clinic. The standard premium is $202.90 a month in 2026, with a $283 deductible and 20% coinsurance after that.

Part C: Medicare Advantage

Private plans that replace Parts A and B with a single plan, usually including drug coverage and extras. They use networks and cap your yearly in-network costs.

Part D: prescription drugs

Private plans that cover outpatient prescription drugs. In 2026 the deductible is at most $615 and out-of-pocket costs are capped at $2,100.

Medigap: the gap filler

Medigap (Medicare Supplement) policies pay some or all of what Parts A and B leave behind: deductibles, coinsurance and the 20% Part B share. They only work with Original Medicare, not with Medicare Advantage. The plan letter guide explains the ten standardized plans.

Two ways to put it together

1. Original Medicare (A + B) + Medigap + Part D.
2. Medicare Advantage (C), usually with drugs included.

Which suits you depends on cost, doctors and travel; see the comparison. For help in Washington, Maru Insurance is an independent, licensed agency.

Questions people ask

Is Medicare free?

Part A is free for most people; Part B has a monthly premium.

Is Medigap a part of Medicare?

No. It is private insurance that supplements Parts A and B.

Can I have Medigap with Medicare Advantage?

No. Medigap only works with Original Medicare.

Do I need Part D?

If you have no other creditable drug coverage, joining avoids a lifetime penalty.

Independent educational site. Not affiliated with or endorsed by the U.S. government, the federal Medicare program, or any insurance company. Figures are 2026 amounts published by CMS unless noted; check Medicare.gov for your situation.