New to Medicare: A Beginner’s Guide to Medicare Parts A, B, C and D

<p>Medicare can feel confusing when you first become eligible. Part A, Part B, Part C, Part D, Medicare Advantage and Medicare Supplement plans all have different purposes, and understanding how they fit together can make your Medicare decisions much easier.</p>

<p><strong>Quick answer:</strong> Original Medicare consists of Part A and Part B. Part A primarily covers hospital and inpatient care, while Part B covers doctors, outpatient care and other medical services. Part C is another name for Medicare Advantage, an alternative way to receive your Medicare benefits through a Medicare-approved private insurance company. Part D provides prescription drug coverage.</p>

<p>For a broader overview of Medicare coverage, costs, plan options and enrollment, see our complete guide to <a href="/blogs/medicare/medicare-in-california">Medicare in California</a>.</p>

<h2>What Is Medicare?</h2>

<p>Medicare is federal health insurance primarily for people age 65 and older. Some people under 65 can also qualify because of certain disabilities or medical conditions.</p>

<p>When you become eligible for Medicare, one of the first things to understand is that Medicare is divided into different parts.</p>

<ul>
  <li><strong>Part A:</strong> Hospital Insurance</li>
  <li><strong>Part B:</strong> Medical Insurance</li>
  <li><strong>Part C:</strong> Medicare Advantage</li>
  <li><strong>Part D:</strong> Prescription Drug Coverage</li>
</ul>

<p>There is also Medicare Supplement Insurance, commonly called Medigap, which is separate from Parts A, B, C and D.</p>

<h2>What Is Medicare Part A?</h2>

<p>Medicare Part A is commonly called hospital insurance.</p>

<p>Part A helps cover:</p>

<ul>
  <li>Inpatient hospital care</li>
  <li>Skilled nursing facility care when Medicare requirements are met</li>
  <li>Hospice care</li>
  <li>Certain home health care</li>
</ul>

<p>Many people qualify for premium-free Part A because they or their spouse paid Medicare taxes for a sufficient period while working. People who do not qualify for premium-free Part A may be able to purchase it.</p>

<p>Part A does not mean that every hospital-related expense is free. Deductibles, coinsurance and other cost-sharing can apply.</p>

<p>For a more detailed comparison, see our guide to <a href="/blogs/medicare/medicare-part-a-vs-part-b">Medicare Part A vs. Part B</a>.</p>

<h2>What Is Medicare Part B?</h2>

<p>Medicare Part B is commonly called medical insurance.</p>

<p>Part B helps cover services such as:</p>

<ul>
  <li>Doctors and other health care providers</li>
  <li>Outpatient care</li>
  <li>Many preventive services</li>
  <li>Durable medical equipment</li>
  <li>Certain home health services</li>
</ul>

<p>Unlike premium-free Part A, Part B generally has a monthly premium. Some people pay more than the standard Part B premium based on income.</p>

<p>Part B can also have deductibles and coinsurance for covered services.</p>

<h2>What Are Original Medicare Parts A and B?</h2>

<p>When Part A and Part B are used together through the federal Medicare program, this is called <strong>Original Medicare</strong>.</p>

<p>With Original Medicare, you can generally use any doctor or hospital in the United States that accepts Medicare.</p>

<p>Original Medicare does not include most prescription drug coverage. If you want prescription drug coverage, you can generally add a separate Medicare Part D plan.</p>

<p>You may also be able to purchase Medicare Supplement Insurance, or Medigap, to help with certain out-of-pocket costs left by Original Medicare.</p>

<h2>What Is Medicare Part C?</h2>

<p>Medicare Part C is another name for <strong>Medicare Advantage</strong>.</p>

<p>Medicare Advantage is an alternative way to receive your Medicare Part A and Part B benefits. These plans are offered by private insurance companies approved by Medicare.</p>

<p>To join a Medicare Advantage plan, you generally must have both Medicare Part A and Part B.</p>

<p>Medicare Advantage plans provide your Part A and Part B benefits and most plans also include Part D prescription drug coverage.</p>

<p>Many Medicare Advantage plans offer additional benefits that Original Medicare does not cover, which may include certain dental, vision or hearing benefits.</p>

<p>Plans can also have provider networks, service areas, copayments and rules for obtaining certain services.</p>

<p>Learn more in our guide to <a href="/blogs/medicare/original-medicare-vs-medicare-advantage">Original Medicare vs. Medicare Advantage</a>.</p>

<h2>What Is Medicare Part D?</h2>

<p>Medicare Part D provides prescription drug coverage.</p>

<p>Part D coverage is offered through private insurance companies that follow Medicare rules.</p>

<p>If you have Original Medicare, you can generally purchase a separate Medicare Part D prescription drug plan.</p>

<p>If you choose Medicare Advantage, prescription drug coverage is included in most Medicare Advantage plans.</p>

<p>Part D plans can differ in:</p>

<ul>
  <li>Monthly premiums</li>
  <li>Deductibles</li>
  <li>Covered medications</li>
  <li>Drug tiers</li>
  <li>Copayments and coinsurance</li>
  <li>Pharmacy networks</li>
</ul>

<p>Because plans can cover medications differently, reviewing your prescriptions when comparing Part D coverage is important.</p>

<p>See our complete guide to <a href="/blogs/medicare/medicare-part-d-prescription-drug-coverage">Medicare Part D and prescription drug coverage</a>.</p>

<h2>What Is Medigap?</h2>

<p>Medicare Supplement Insurance, commonly called Medigap, is private insurance designed to work with Original Medicare.</p>

<p>A Medigap policy can help pay certain out-of-pocket costs left by Original Medicare, such as applicable copayments, coinsurance and deductibles, depending on the plan.</p>

<p>Medigap is <strong>not</strong> Medicare Part C and is not the same thing as Medicare Advantage.</p>

<p>Generally, you must have Original Medicare Part A and Part B to purchase a Medigap policy.</p>

<p>You cannot use a Medigap policy to pay Medicare Advantage plan copayments, deductibles or premiums.</p>

<p>Learn more in our comparison of <a href="/blogs/medicare/medicare-advantage-vs-medigap">Medicare Advantage vs. Medicare Supplement (Medigap)</a>.</p>

<h2>What Are the Two Main Ways to Get Medicare Coverage?</h2>

<p>Once you have Medicare Part A and Part B, there are two primary ways to receive your Medicare coverage.</p>

<h3>Option 1: Original Medicare</h3>

<p>Original Medicare includes:</p>

<ul>
  <li>Medicare Part A</li>
  <li>Medicare Part B</li>
</ul>

<p>You can also choose to add:</p>

<ul>
  <li>A separate Part D prescription drug plan</li>
  <li>A Medicare Supplement, or Medigap, policy if eligible</li>
</ul>

<h3>Option 2: Medicare Advantage</h3>

<p>Medicare Advantage, also known as Part C, provides your Medicare benefits through a Medicare-approved private insurance company.</p>

<p>Medicare Advantage plans include Part A and Part B benefits, and most plans also include Part D prescription drug coverage.</p>

<p>The two approaches can differ significantly in provider access, costs, plan rules, additional benefits and how your coverage is structured.</p>

<p>See <a href="/blogs/medicare/original-medicare-vs-medicare-advantage">Original Medicare vs. Medicare Advantage</a> for a detailed comparison.</p>

<h2>When Do I Sign Up for Medicare?</h2>

<p>For most people who become eligible for Medicare at age 65, the Initial Enrollment Period is a seven-month period.</p>

<p>It generally begins:</p>

<ul>
  <li>Three months before the month you turn 65</li>
  <li>Includes the month you turn 65</li>
  <li>Ends three months after the month you turn 65</li>
</ul>

<p>Your situation can be different if you already receive certain Social Security or Railroad Retirement Board benefits, qualify for Medicare before age 65, or have health coverage through current employment.</p>

<p>Signing up late can sometimes result in coverage gaps or late-enrollment penalties.</p>

<p>See our guide to <a href="/blogs/medicare/medicare-enrollment-when-how-to-sign-up">Medicare enrollment and when to sign up</a>.</p>

<h2>What if I'm Still Working at 65?</h2>

<p>Turning 65 does not automatically mean everyone should make the same Medicare enrollment decision.</p>

<p>If you or your spouse are actively working and you have employer-sponsored health insurance, the rules can depend on the type of coverage and the employer.</p>

<p>Some people may be able to delay Part B without a late-enrollment penalty and later use a Special Enrollment Period. Other people may need Medicare when they first become eligible for their existing coverage to work properly.</p>

<p>COBRA and retiree coverage can also have different Medicare enrollment rules than insurance based on current employment.</p>

<p>See <a href="/blogs/medicare/working-past-65-medicare">Working Past 65: Do You Need to Sign Up for Medicare?</a> before assuming you should delay enrollment.</p>

<h2>Do I Automatically Get Medicare When I Turn 65?</h2>

<p>Not everyone needs to manually enroll.</p>

<p>Some people who are already receiving Social Security or Railroad Retirement Board benefits may be automatically enrolled in Medicare Part A and Part B when they become eligible.</p>

<p>Others need to actively sign up for Medicare.</p>

<p>Because enrollment circumstances vary, check your individual enrollment status rather than assuming coverage will automatically begin.</p>

<h2>Do I Have to Choose Medicare Advantage?</h2>

<p>No. Medicare Advantage is an alternative to receiving your benefits through Original Medicare.</p>

<p>People with Medicare can choose between Original Medicare and Medicare Advantage when they are eligible to make that choice.</p>

<p>Neither option is structured exactly like the other, so it is important to understand provider access, prescriptions, premiums, out-of-pocket costs and plan rules before selecting coverage.</p>

<h2>Do I Need Medicare Part D?</h2>

<p>Part D is optional, but going without Medicare drug coverage or other creditable prescription drug coverage for too long can result in a Part D late-enrollment penalty if you enroll later.</p>

<p>If you already have prescription coverage through an employer, union or another source, determine whether that coverage is considered creditable before deciding to delay Part D.</p>

<p>Keep any creditable coverage notices you receive for your records.</p>

<h2>Can I Change My Medicare Coverage Later?</h2>

<p>There are specific enrollment periods when Medicare beneficiaries may be able to change coverage.</p>

<p>One of the best known is Medicare Open Enrollment, which occurs each year from October 15 through December 7.</p>

<p>During this period, eligible Medicare beneficiaries can make certain changes involving Medicare Advantage and Medicare prescription drug coverage for the following year.</p>

<p>See our guide to <a href="/blogs/medicare/medicare-open-enrollment">Medicare Open Enrollment 2027</a> for dates, deadlines and available changes.</p>

<h2>Frequently Asked Questions</h2>

<h3>What are the four parts of Medicare?</h3>

<p>Medicare Part A is Hospital Insurance, Part B is Medical Insurance, Part C is Medicare Advantage and Part D provides prescription drug coverage.</p>

<h3>Are Medicare Part A and Part B Original Medicare?</h3>

<p>Yes. Original Medicare consists of Medicare Part A and Medicare Part B.</p>

<h3>Is Medicare Advantage the same as Part C?</h3>

<p>Yes. Medicare Advantage is also called Medicare Part C. It is an alternative way to receive Medicare benefits through a Medicare-approved private insurance company.</p>

<h3>Is Medigap the same as Medicare Advantage?</h3>

<p>No. Medigap supplements Original Medicare, while Medicare Advantage is an alternative way to receive your Medicare benefits. They are different types of coverage.</p>

<h3>Does Original Medicare include prescription drugs?</h3>

<p>Original Medicare does not include most outpatient prescription drug coverage. People with Original Medicare can generally enroll in a separate Medicare Part D plan for prescription drug coverage.</p>

<h3>When should I start learning about Medicare?</h3>

<p>If you expect to become eligible at 65, it is helpful to begin learning about Medicare before your Initial Enrollment Period begins so you have time to understand enrollment deadlines and your coverage choices.</p>

<p><em>This article is for general educational and informational purposes. Medicare eligibility, enrollment rules, costs, benefits and plan availability can vary based on individual circumstances and may change over time. For official Medicare information, visit Medicare.gov or call 1-800-MEDICARE.</em></p>