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).

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

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. Medicare Advantage plans may also offer benefits not covered by Original Medicare. 

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.

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.

If you're looking for Medicare prescription drug coverage, you can consider enrolling in a Medicare Advantage Prescription Drug (MA-PD) plan or 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 senior Medicare and health insurance writer with He is also a licensed health insurance agent. Christian is well-known in the insurance industry for the thousands of educational articles he’s written, helping Americans better understand their health insurance and Medicare coverage.

Christian’s work as a Medicare expert has appeared in several top-tier and trade news outlets including Forbes, MarketWatch, WebMD and Yahoo! Finance.

Christian has written hundreds of articles for that teach Medicare beneficiaries the best practices for navigating Medicare. His articles are read by thousands of older Americans each month. By better understanding their health care coverage, readers may hopefully learn how to limit their out-of-pocket Medicare spending and access quality medical care.

Christian’s passion for his role stems from his desire to make a difference in the senior community. He strongly believes that the more beneficiaries know about their Medicare coverage, the better their overall health and wellness is as a result.

A current resident of Raleigh, Christian is a graduate of Shippensburg University with a bachelor’s degree in journalism.

If you’re a member of the media looking to connect with Christian, please don’t hesitate to email our public relations team at

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1 10-minute claim is based solely on the time to complete the e-application if you have your Medicare card and other pertinent information available when you apply. The time to shop for plans, compare rates, and estimate drug costs is not factored into the claim. Application time could be longer. Actual time to enroll will depend on the consumer and their plan comparison needs.