Common Questions

Medicare Parts A, B, C and D

Original Medicare consists of Part A and Part B. Other coverage options include Medicare Advantage plans (Part C) and Medicare prescription drug coverage (Part D).

There are four different parts of Medicare: Part A, Part B, Part C, and Part D — each part covering different services.

Understanding how these parts and services work (together and separately) is the key to determining which ones fit your unique health care needs and budget.

There are two main paths for Medicare coverage — enrolling in Original Medicare (Parts A and B) or enrolling in a Medicare Advantage plan (Part C).

Find a $0 premium Medicare Advantage plan today.

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Either path can include prescription drug coverage (Part D).

Seniors traveling and looking at a map

Original Medicare (Part A and Part B)

Original Medicare — sometimes referred to as “traditional” Medicare — is administered by the federal government. It is divided into two parts: Part A (hospital insurance) and Part B (medical insurance).

Medicare Part A

Medicare Part A covers hospital care, including, skilled nursing facilities, hospice, and some home health care.

Medicare Part B

Medicare Part B is “optional” medical insurance that covers a range of outpatient services — including physician and specialist office visits, preventive care, lab work, medical equipment, physical therapy, mental health care and wellness visits.

Who is eligible?

Generally, you become eligible to receive Medicare benefits when you turn 65 years old ― assuming you meet certain citizenship or residency requirements. There are exceptions made to the age requirement for those with disabilities and End-Stage Renal Disease.

For those younger than 65, you are only eligible to receive Medicare benefits if you:

  • Have received Social Security or Railroad Retirement Board (RRB) disability benefits for 24 months
  • Have End-Stage Renal Disease (ESRD)
  • Have been diagnosed with Lou Gehrig’s disease (ALS)

Signing up for Original Medicare

Some people qualify for automatic enrollment, and others have to enroll.

  • If you’re already receiving Social Security or railroad retirement benefits — you’ll be enrolled in Part A and Part B automatically on your 65th birthday.

    If you’re under 65, it’s the 25th month you receive disability benefits.

  • ALS patients are automatically enrolled in Medicare coverage when their Social Security disability benefits begin, regardless of age.

    If you have end-stage renal disease (ESRD), you must manually enroll.

If you’re eligible for Medicare but don’t qualify for automatic enrollment, you can apply online, over the phone or in person at your local Social Security office.

If you worked for a railroad, you’ll need to contact the Railroad Retirement Board for information on enrollment.

Medicare Advantage plans (Part C)

Medicare Advantage (Part C) is an alternative to Original Medicare. It allows you to receive Part A and Part B benefits — and in many cases, other benefits — from a private health insurance plan.

At the very least, your Medicare Advantage plan must offer the same benefits as Original Medicare. The only exception is hospice care, which is still covered by Medicare Part A.

Additional benefits that many Medicare Advantage plans include are:

  • Vision coverage
  • Hearing coverage
  • Dental coverage
  • Medicare Part D prescription drug coverage

If you’re eligible for Medicare Part A and Part B, and do not have ESRD, you can join a Medicare Advantage Plan.

Medicare beneficiaries have the option of receiving health care benefits through either Medicare Advantage or Original Medicare — but not both. You need to enroll in Part A and Part B to sign up for a Medicare Advantage plan.

Because private insurance companies offer Medicare Advantage plans, costs can vary between policies.

They may have different premiums and out-of-pocket costs than Original Medicare. With a Medicare Advantage plan, you must pay your Part B premium in addition to the plan premium.

Some Medicare Advantage plans feature $0 monthly premiums.

Medicare prescription drug coverage (Part D)

Medicare Prescription Drug Coverage (Part D) helps cover your prescription drug costs.

Prescription Drug Plans (PDPs) can be purchased as stand-alone plans from private insurers in addition to Original Medicare or Medicare Advantage plans that don’t offer drug coverage.

Many Medicare Advantage plans also include Part D coverage.

If you're looking for Medicare prescription drug coverage, you can consider enrolling in a Medicare Advantage plan that includes drug coverage, or you can consider enrolling in a Medicare Part D plan.

You can compare Part D plans available where you live and enroll in a Medicare prescription drug plan online in as little as 10 minutes when you visit

Speak with a licensed agent today

To learn more about your Medicare options — Part A, B, C or D — and to learn more about the benefits that might be available in Medicare Advantage plans in your area, call today to speak with a licensed insurance agent.


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About the author

Christian Worstell is a licensed insurance agent and a Senior Staff Writer for He is passionate about helping people navigate the complexities of Medicare and understand their coverage options.

His work has been featured in outlets such as Vox, MSN, and The Washington Post, and he is a frequent contributor to health care and finance blogs.

Christian is a graduate of Shippensburg University with a bachelor’s degree in journalism. He currently lives in Raleigh, NC.

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