What are the different parts of Medicare? A detailed Medicare explanation

Medicare can feel overwhelming at first. You hear terms like Part A, Part B, Part C, Part D, and Medigap, but no one explains how they fit together in simple terms.

Medicare is not one single plan. The different parts of Medicare cover a specific type of care. Understanding how these parts work together helps you avoid coverage gaps, surprise costs, and enrollment mistakes.

“Understanding Medicare parts isn’t optional. It’s the first step to protecting both your health and your finances and making confident healthcare choices for the future.”

What Are the Different Parts of Medicare?

Medicare is the federal health insurance program for people age 65 and older, as well as certain younger individuals with disabilities or specific medical conditions. More than 66 million Americans are enrolled in Medicare today, and that number continues to grow each year.

Yet many beneficiaries enroll without fully understanding the different Medicare parts, which often leads to coverage gaps, unexpected bills, or late-enrollment penalties. If you’re also trying to understand how Medicare compares to other coverage options, this guide on Medicare vs Medicaid vs private insurance helps clarify who pays first and how coverage differs.

When people ask, “What are the Medicare parts?” they’re usually referring to four core components:

• Medicare Part A: Hospital Insurance (inpatient care).

• Medicare Part B: Medical Insurance (outpatient care/doctors).

• Medicare Part C: Medicare Advantage (private alternative bundling A, B, and usually D).

• Medicare Part D: Prescription Drug Coverage. 

• Medicare Supplement (Medigap): In addition, many people also choose a Medicare Supplement plan (Medigap) to help cover out-of-pocket costs.

Medicare Part A vs B: The Foundation of Your Coverage

At the core of Medicare is Original Medicare, which includes Parts A and B. If you’re wondering what are Medicare Parts A and B, they work together to cover hospital care and outpatient medical services.

Medicare Part A: Hospital Insurance

Medicare Part A is often referred to as hospital insurance. It is mainly paid for through payroll taxes you or your spouse contributed while working. If those Medicare taxes were paid for at least 10 years, Medicare Part A is usually premium-free.

What Medicare Part A Covers

Medicare Part A helps cover the most serious care needs when hospitalization or skilled care is required.

• Inpatient Hospital Care: Includes semi-private rooms, meals, nursing services, and medications you receive during a hospital stay.

• Skilled Nursing Facility (SNF) Care: Covered only after a qualifying 3-day inpatient hospital stay.

• Hospice Care: Support and comfort care for terminally ill patients with a life expectancy of six months or less.

• Home Health Care: Limited part-time or intermittent skilled nursing and related services at home.

“For example, if you’re admitted to the hospital after a surgery, Medicare Part A helps pay for your hospital room, daily meals, nursing support, and the medications you receive while you’re there.”

What Medicare Part A Does Not Cover

Medicare Part A does not cover long-term custodial care, personal care assistance, most outpatient services, or private rooms, and with a high deductible, it is essential but not comprehensive.

Medicare Part B: Medical Insurance

Medicare Part B covers outpatient and preventive medical services and works like standard health insurance. Unlike Part A, it requires a monthly premium, which may vary based on income.

What Medicare Part B covers

• Doctor visits and specialist care

• Outpatient services and surgeries

• Preventive services like screenings, vaccines, and wellness visits

• Lab tests and diagnostic services

• Durable medical equipment, such as wheelchairs and oxygen

• Mental health services

Simply put, Part A covers the hospital, while Medicare Part B covers the doctors and care you receive inside and outside the hospital.

Medicare Parts A and B Coverage Together

When people ask "what does Medicare Parts A and B cover?", the short answer is hospital care plus medical care.

Together, Medicare Part A and Medicare Part B cover roughly 80 percent of approved healthcare costs, leaving beneficiaries responsible for deductibles, coinsurance, and services Medicare doesn’t include.

This step-by-step guide on Medicare crossover claims explains how secondary insurance works when Medicare pays first.

Medicare Part C and D: Beyond Original Medicare

After understanding Medicare Parts A and B, many people look for coverage that goes beyond Original Medicare. This is where Medicare Part C and Medicare Part D come into play.

Medicare Part C: Medicare Advantage

Medicare Part C, called Medicare Advantage, is provided by private insurance companies that are approved by Medicare.

What Medicare Part C Covers:

• All benefits from Medicare Part A and Part B

• Hospital and medical services you would get under Original Medicare

• Often includes prescription drug coverage (Part D)

Medicare Advantage plans must meet Medicare’s rules, but benefits, costs, and provider networks can vary by plan.

Medicare Part D: Prescription Drug Coverage

Medicare Part D helps to cover the cost of prescription drugs. If you stay with Original Medicare, you must enroll in Part D separately.

What Medicare Part D Covers

• Retail and mail-order prescription drugs

• Tiered drug pricing based on formulary

• Protection against high drug costs through catastrophic coverage

On average, Part D enrollees save thousands annually on medication costs compared to paying out of pocket.

Understanding Medicare Parts B and D together is important, especially for people managing chronic conditions.

Medicare Supplement (Medigap)

Medicare Supplement plans, often called Medigap, are designed to help cover the costs that Original Medicare doesn’t fully pay on its own.

Original Medicare (Parts A and B) pays for much, but not all, of the cost for covered health care services and supplies. It does not cover the "gaps" like copayments, coinsurance, and deductibles. 

There are multiple types of Medicare supplement plans, labeled Plan A through Plan N. Each plan offers a standardized set of benefits, though pricing varies by insurer and location.

“For example, you might choose Plan G to limit out-of-pocket costs, except for the Part B deductible. Remember, Medigap works only with Original Medicare, not Medicare Advantage.”

How and When to Choose the Best Medicare Parts

Start with Medicare Part A. If you qualify for premium-free Part A, enroll. It’s your hospital coverage base.

Next, add Medicare Part B unless you have active employer coverage. Part B covers doctor visits and outpatient care, and delaying it without the right coverage can cost you later.

Then make the big choice: Original Medicare vs. Medicare Advantage (Part C).

Original Medicare offers broader provider choice and pairs well with Part D and Medigap. Medicare Advantage bundles coverage but uses networks. Always compare prescriptions and review annually.

Practical Strategy for Choosing Medicare Parts

Start with these steps:

• Confirm eligibility for premium-free Part A

• Enroll in Part B unless you have employer coverage

• Compare Original Medicare vs Medicare Advantage

• Evaluate prescription drug needs carefully

• Consider Medigap during your guaranteed issue window

People who plan save significantly over time. According to CMS data, beneficiaries who review their coverage annually reduce unnecessary healthcare spending by up to 30 percent. This 8-minute rule cheat sheet is a helpful reference for Medicare billing accuracy.

FAQ

1. What are the Medicare parts?

The Medicare parts include Part A (hospital insurance), Part B (medical insurance), Part C (Medicare Advantage), and Part D (prescription drug coverage).  Many people also use Medigap to help cover extra costs.

2. What do Medicare Parts A and B cover?

Medicare Parts A and B coverage includes inpatient hospital care, outpatient medical services, preventive care, diagnostic testing, and certain home health services. However, they do not cover all healthcare costs.

3. What does Medicare Part A not cover?

Medicare Part A does not cover long-term custodial care, private duty nursing, personal care assistance, or most outpatient services. These gaps often require supplemental coverage.

Conclusion

Medicare doesn’t have to be confusing.

Once you understand what are the different parts of Medicare?, everything else starts to make sense. Knowing how Medicare Parts A and B work, when Medicare Part C and D apply, and where Medigap fits helps you make confident coverage decisions.

If you’re not sure which Medicare parts are right for you, it’s a good idea to review your options or book a call with a Medicare professional. A small decision today can help you avoid bigger problems later.