The four parts of Medicare, side by side

Part A, Part B, Part C and Part D do different jobs. Here's what each one covers and how they fit together — then call and we'll work out which shape fits you.

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At a glance

What each part covers

Costs are set annually and vary by plan and county, so figures aren’t listed here — an agent can tell you the current numbers for your area.

Medicare Parts A, B, C and D — what each covers, how you get it, and how costs work
Part	What it covers	How you get it	How costs work
Part AHospital insurance	Inpatient hospital stays, skilled nursing facility care, hospice, and some home health care.	Part of Original Medicare, from the federal government.	Premium-free for most people who paid Medicare taxes long enough while working. Deductibles and coinsurance apply and are set each year.
Part BMedical insurance	Doctor visits, outpatient care, preventive services, lab work, and durable medical equipment.	Part of Original Medicare, from the federal government.	A standard monthly premium set each year, higher for higher incomes, plus an annual deductible and typically 20% coinsurance.
Part CMedicare Advantage	Everything Parts A and B cover, at minimum. Often bundles Part D, and may add dental, vision, hearing or fitness benefits.	An alternative route — a private plan approved by Medicare replaces how you receive your benefits.	Varies by plan; some have no additional premium. You keep paying your Part B premium. Every plan has an annual out-of-pocket maximum.
Part DPrescription drug coverage	Prescription medications, according to each plan's own formulary and tiers.	A private plan, either standalone alongside Original Medicare or built into a Part C plan.	Varies by plan. A late enrollment penalty can apply if you go without creditable drug coverage.

How they fit together

Two common routes

Original Medicare, built up

Parts A and B from the government, usually plus a Medicare Supplement plan to help with your share of the costs, plus a standalone Part D plan for prescriptions.

Any provider that accepts Medicare · no networks · three pieces to manage

Medicare Advantage, all in one

Parts A and B, received through a single private Part C plan that usually includes prescription coverage and may add dental, vision or hearing benefits.

Network-based · annual out-of-pocket maximum · one plan to manage

You choose one route or the other — a Supplement plan can’t be used with an Advantage plan.

Timing

When you can make changes

Initial Enrollment Period

A seven-month window: the three months before the month you turn 65, that month, and the three months after.

Annual Enrollment Period

October 15 to December 7 each year. You can join, switch or drop a Medicare Advantage or Part D plan; changes take effect January 1.

Medicare Advantage Open Enrollment

January 1 to March 31, if you're already in an Advantage plan. You can switch once to another Advantage plan or return to Original Medicare.

Medigap Open Enrollment

Six months beginning when your Part B coverage starts. Inside it you can generally buy any Supplement plan sold in your area regardless of health.

Questions about how Medicare works

What's the difference between Original Medicare and Medicare Advantage?

Original Medicare is Parts A and B together, provided by the federal government, and you can use any provider that accepts Medicare. Medicare Advantage (Part C) is a private plan that becomes the way you receive those same benefits, usually through a network, often with drug coverage and extras bundled in. It's a fork in the road rather than an add-on — you go one way or the other.

Do I have to take Part B?

Not necessarily, but delaying it without other creditable coverage can mean a permanent late enrollment penalty. If you're still working and covered by an employer plan, the right answer depends on the size of that employer and how the coverage is structured — which is a good reason to ask before deciding.

Which parts do I actually need?

Most people end up with either Parts A and B plus a Supplement plan and a Part D plan, or Parts A and B plus a Medicare Advantage plan that bundles drug coverage. Which of those two shapes fits you depends on your doctors, your prescriptions, whether you travel, and how you'd rather handle costs.

What happens if I miss my enrollment window?

It depends on which window and why. Some late enrollments carry a lasting penalty, and some situations open a special enrollment period that lets you act outside the normal dates. If you think you've missed something, it's worth a call sooner rather than at the next deadline.

Still working out where you fit?

Most people are. Tell a licensed agent about your doctors and prescriptions and they’ll explain your options — no cost, no obligation.

Call (855) 764-2227

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