A clear introduction to Medicare Parts A, B, C and D

Medicare choices affect doctors, prescriptions and out-of-pocket costs. Start with howthe parts work together, then compare options available in your ZIP code.

Reviewed 2026-07-30 Reviewed by our licensed insurance experts.

01 — The four parts

What each part generally covers

Part A- Hospital

Inpatient hospital care, skilled nursing facility care, hospice and some home health care.

Part B- Medical

Doctor services, outpatient care, preventive services and certain medical equipment.

Part C- Medicare Advantage

An alternative way to receive Parts A and B through a Medicare-approved private plan; most include Part D.

Part D - Prescription drugs

Coverage for prescription medications through a stand-alone drug plan or many Medicare Advantage plans.

02 — Compare paths

Original Medicare vs. Medicare Advantage

Even when a Medicare Advantage plan has a So plan premium, members generally must continue paying the Part B premium. Benefits and costs vary by plan and county.

03 — Enrollment

Avoid timing surprises

Your Initial Enrollment Period is tied to when you first become eligible. Other enrollmentperiods may apply if you have qualifying employer coverage or specific circumstances.Late-enrollment penalties can apply in some situations, so review current coverage beforedelaying Part B or Part D.

A clear introduction to Medicare Parts A, B, C and D

What each part generally covers

Part A- Hospital

Part B- Medical

Part C- Medicare Advantage

Part D - Prescription drugs

Original Medicare vs. Medicare Advantage

Avoid timing surprises

Related resources

Enrollment timing

Choosing a plan

Small-business benefits