Do I have to choose a Medicare Part C plan?

No, choosing a Medicare Part C (Medicare Advantage) plan is optional. You can choose to stick with Original Medicare (Parts A and B) instead. Part C is an alternative way to get your Medicare benefits through a private company, not a requirement.

What is the difference between Medicare Part B and Part D?

Medicare Part B covers medical services like doctor visits, outpatient care, and some medical equipment. Medicare Part D specifically helps cover the cost of prescription drugs you pick up at a pharmacy. They cover different types of healthcare needs.

Can I have Medicare Part C and a separate Part D plan?

Most Medicare Part C plans (Medicare Advantage) already include prescription drug coverage (Part D). If your Part C plan does not, you might be able to add a separate Part D plan, but this is less common. It's important to check your specific plan details to avoid any issues or duplicate coverage.

When can I sign up for Medicare?

There are specific times you can enroll in Medicare. Your Initial Enrollment Period is typically around your 65th birthday. There's also an Annual Enrollment Period each fall to make changes to your existing coverage. Missing these periods can sometimes lead to late enrollment penalties.

What is Medigap, and how does it fit in?

Medigap, or Medicare Supplement Insurance, is private insurance that helps pay some of the costs that Original Medicare (Parts A and B) doesn't cover. These costs can include deductibles and copayments. You cannot have a Medigap policy if you are enrolled in a Medicare Part C plan; it works only with Original Medicare.

Medicare Explained

What Are Medicare Parts A, B, C, and D, and What Do They Cover?

Medicare is a federal health insurance program for eligible individuals. It's divided into different parts, each covering specific health services like hospital care, doctor visits, and prescription drugs. Understanding these parts helps you choose the right coverage for your healthcare needs.

By the ExplainMyBill.ai Editorial Team · Reviewed by our billing research team

Published June 5, 2026 · Updated June 5, 2026

What is Medicare, and Why Does it Have Different Parts?

Medicare is a federal health insurance program. It mainly helps people age 65 or older. It also helps younger people with certain disabilities. People with permanent kidney failure needing dialysis or a transplant also qualify.

Medicare is split into different parts. Each part covers specific kinds of health services. This structure can seem confusing at first. But knowing what each part does will help you make good choices for your health coverage.

Medicare Part A: Hospital Insurance

Medicare Part A is often called Hospital Insurance. It helps pay for care you get when you are admitted to a hospital. Most people do not pay a monthly premium for Part A if they or their spouse paid Medicare taxes through work for a certain number of years.

Think of Part A as covering your stays in a medical facility, not just a doctor's visit.

Inpatient hospital stays
Care in a skilled nursing facility (after a hospital stay)
Hospice care
Some home health care

Medicare Part B: Medical Insurance

Medicare Part B is Medical Insurance. It covers services from doctors and other health care providers. It also covers outpatient care. You typically pay a monthly premium for Part B. This premium is often taken directly from your Social Security benefit.

Part B helps you get the routine and necessary care you need outside of a hospital admission.

Doctor visits and other outpatient services
Preventive services (like flu shots and screenings)
Outpatient hospital care
Some durable medical equipment (like wheelchairs or oxygen)
Mental health services

Medicare Part C: Medicare Advantage Plans

Medicare Part C is also known as Medicare Advantage. These plans are offered by private insurance companies approved by Medicare. If you choose a Part C plan, it replaces your Original Medicare (Parts A and B).

Medicare Advantage plans must cover everything that Original Medicare (Parts A and B) covers. Many plans also offer extra benefits that Original Medicare does not. You still pay your Part B premium, and often a separate premium to the Part C plan.

Combines Part A, Part B, and often Part D (prescription drugs)
May include extra benefits like dental, vision, or hearing care
Often has a network of doctors and hospitals you must use
May have different out-of-pocket costs than Original Medicare

Medicare Part D: Prescription Drug Coverage

Medicare Part D helps cover the cost of prescription drugs. These plans are offered by private insurance companies. You can get Part D in two ways: as a stand-alone plan if you have Original Medicare (Parts A and B), or as part of a Medicare Advantage (Part C) plan.

Part D plans have different lists of covered drugs, called formularies. They also have different costs and coverage stages. It's important to compare plans based on the medications you take.

Helps pay for prescription medications
Offered by private insurance companies
Can be added to Original Medicare (A & B)
Often included in Medicare Advantage (Part C) plans

Making Your Medicare Choice: Original vs. Advantage

Understanding these parts helps you choose how you get your Medicare benefits. You can choose Original Medicare (Parts A and B). If you choose this path, you might add a separate Part D plan for prescriptions. Many people with Original Medicare also buy a Medigap policy. Medigap helps pay some of the costs that Original Medicare doesn't cover, like deductibles and copayments.

Your other option is a Medicare Advantage (Part C) plan. This plan bundles your Part A, Part B, and often Part D coverage into one plan from a private company. You cannot have a Medigap policy if you are enrolled in a Medicare Advantage plan.

The best choice depends on your health, your budget, and what doctors and hospitals you want to use. Review your options carefully each year during the open enrollment period. You can visit Medicare.gov or speak with a trusted advisor for personalized help.

Frequently asked questions

Do I have to choose a Medicare Part C plan?: No, choosing a Medicare Part C (Medicare Advantage) plan is optional. You can choose to stick with Original Medicare (Parts A and B) instead. Part C is an alternative way to get your Medicare benefits through a private company, not a requirement.
What is the difference between Medicare Part B and Part D?: Medicare Part B covers medical services like doctor visits, outpatient care, and some medical equipment. Medicare Part D specifically helps cover the cost of prescription drugs you pick up at a pharmacy. They cover different types of healthcare needs.
Can I have Medicare Part C and a separate Part D plan?: Most Medicare Part C plans (Medicare Advantage) already include prescription drug coverage (Part D). If your Part C plan does not, you might be able to add a separate Part D plan, but this is less common. It's important to check your specific plan details to avoid any issues or duplicate coverage.
When can I sign up for Medicare?: There are specific times you can enroll in Medicare. Your Initial Enrollment Period is typically around your 65th birthday. There's also an Annual Enrollment Period each fall to make changes to your existing coverage. Missing these periods can sometimes lead to late enrollment penalties.
What is Medigap, and how does it fit in?: Medigap, or Medicare Supplement Insurance, is private insurance that helps pay some of the costs that Original Medicare (Parts A and B) doesn't cover. These costs can include deductibles and copayments. You cannot have a Medigap policy if you are enrolled in a Medicare Part C plan; it works only with Original Medicare.

This article is educational information, not medical, legal, or financial advice. Billing rules change and individual situations vary — always confirm details with your provider or insurer.