medicare parts explained

February 24, 2026

Medicare has four main parts: Part A (hospital), Part B (medical), Part C (Medicare Advantage), and Part D (drug coverage), plus optional Medigap policies that help with out‑of‑pocket costs. Together, Parts A and B are called “Original Medicare,” and you can choose to stay with Original Medicare or get your coverage through a Part C (Advantage) plan instead.

What Medicare Is

Medicare is a U.S. federal health insurance program mainly for people 65+ and some younger people with disabilities or certain diseases. It helps pay for hospital stays, doctor visits, preventive care, and prescription drugs, but you still have premiums, deductibles, and copays depending on which parts you choose.

Part A – Hospital Insurance

Part A is hospital insurance and is one half of Original Medicare. It generally helps cover:

Inpatient hospital stays
Skilled nursing facility care (after a qualifying hospital stay)
Hospice care for terminal illness
Some home health care services

Most people do not pay a monthly premium for Part A if they or a spouse worked and paid Medicare taxes long enough; others may owe a premium that changes each year.

Part B – Medical Insurance

Part B is medical insurance and is the other half of Original Medicare. It usually covers:

Doctor and specialist visits
Outpatient care and many lab tests
Preventive services (screenings, shots, annual “Wellness” visit)
Durable medical equipment like wheelchairs or walkers

Part B has a monthly premium, an annual deductible, and cost‑sharing (like 20% coinsurance for many services) after the deductible. Premiums can be higher for people with higher incomes.

Part C – Medicare Advantage

Part C, or Medicare Advantage , is an alternative way to get Medicare through private insurers approved by Medicare. Key points:

You still enroll in Medicare, but most of your care is managed by the insurance company’s network
Plans must cover at least what Original Medicare (A and B) covers, and many include Part D drug coverage in one bundle

Often add extras Original Medicare does not cover, like some dental, vision, hearing, or fitness benefits

You still usually pay your Part B premium, plus any extra premium the plan itself charges.

Part D – Prescription Drug Coverage

Part D helps pay for prescription drugs and is offered only through private plans approved by Medicare. You can get it either:

As a stand‑alone drug plan added to Original Medicare
Built into many Medicare Advantage plans (MAPD)

Part D plans have their own monthly premium, drug list (formulary), copays, and rules like prior authorization or preferred pharmacies. The national base beneficiary premium for 2025 is reported as about 36–37 dollars, but your actual premium depends on the plan and your income.

Medigap (Supplement) vs Parts

Medigap is not a “part” of Medicare; it is separate supplemental insurance sold by private companies. Important distinctions:

Medigap helps pay some out‑of‑pocket costs (deductibles, coinsurance) for people on Original Medicare (A and B)
You cannot use Medigap with a Medicare Advantage (Part C) plan; it only works with Original Medicare

Forum discussions frequently warn people not to confuse lettered Medigap plans (like Plan G, Plan N) with the lettered Medicare parts A, B, C, and D.

Key Medicare Pieces at a Glance [5][3] [3] [7][3] [9][5][3] [3] [7][3] [7][9][5] [7][9] [5][3] [5][3] [5] [5] [3][5] [3] [3][5]

Type	Letter	Main Role	Who Offers It	Works With
Hospital insurance	Part A	Inpatient hospital, skilled nursing, hospice, some home health.	Federal Medicare program.	Original Medicare or as part of Advantage.
Medical insurance	Part B	Doctors, outpatient care, preventive services, medical equipment.	Federal Medicare program.	Original Medicare or as part of Advantage.
Medicare Advantage	Part C	All Part A and B services, often Part D and extras like dental/vision.	Private insurers approved by Medicare.	Alternative to Original Medicare (cannot have Medigap with it).
Drug coverage	Part D	Outpatient prescription drugs through plan formularies.	Private insurers approved by Medicare.	Original Medicare (stand‑alone) or built into many Part C plans.
Supplement insurance	Medigap	Helps pay deductibles, coinsurance, and some other gaps in A and B.	Private insurers.	Only with Original Medicare, not with Part C plans.

Information gathered from public forums or data available on the internet and portrayed here.

If you share your age, state, and whether you prefer low monthly costs or more predictable costs when you get care, a more tailored breakdown of which parts and options might fit you can be outlined.