Medicare A, B, C's, & D

Medicare Parts A, B, C, and D

Medicare is divided into different "parts." Each part serves a different purpose.

Medicare Part A: Hospital Insurance

Medicare Part A is primarily hospital insurance.

Part A generally helps cover:

Part A is not simply "everything that happens inside a hospital." Whether Part A or Part B applies can depend on your official patient status and the service you receive.

Most people qualify for premium-free Part A because they or a spouse worked and paid Medicare taxes long enough. People who do not have sufficient Medicare-covered work history may have to pay a monthly premium for Part A.

Does Part A pay 100% of hospital expenses?

No.

Original Medicare has deductibles, coinsurance, and other cost-sharing requirements. Medicare-covered services also must meet applicable coverage requirements.

Part A should therefore not be thought of as unlimited hospital coverage.

Medicare Part B: Medical Insurance

Medicare Part B is primarily medical and outpatient insurance.

Part B generally helps cover:

Unlike premium-free Part A, Part B generally has a monthly premium.

Higher-income beneficiaries may pay an additional income-related amount for Part B known as an Income-Related Monthly Adjustment Amount, or IRMAA.

Part B also generally includes an annual deductible and cost sharing under Original Medicare. Medicare costs can change from year to year.


Medicare Part C: Medicare Advantage

Medicare Part C is another name for Medicare Advantage.

Medicare Advantage is not a separate government benefit added on top of Original Medicare. It is an alternative way to receive your Medicare Part A and Part B benefits through a private insurance company approved by Medicare.

To enroll in a Medicare Advantage plan, you generally must have:

You must continue paying your Medicare Part B premium while enrolled in Medicare Advantage.

Depending on the plan, Medicare Advantage may operate as an:

Most Medicare Advantage plans also include Medicare Part D prescription drug coverage, although some do not.

Plans may also offer additional benefits that Original Medicare generally does not cover, depending on the individual plan and eligibility requirements.

Examples may include certain:

Benefits, provider networks, pharmacies, formularies, premiums, copayments, coinsurance, prior authorization requirements, referral requirements, eligibility rules, and service areas vary by plan and can change from year to year.

There is no Medicare Advantage plan that is automatically best for everyone.

When evaluating a plan, beneficiaries should consider much more than additional benefits. Provider access, prescriptions, anticipated healthcare utilization, plan rules, costs, and personal preferences are all important.

Medicare describes Medicare Advantage as an alternative way to receive Medicare-covered health benefits rather than Original Medicare.


Medicare Part D: Prescription Drug Coverage

Medicare Part D provides prescription drug coverage.

Part D coverage is offered by private insurance companies approved by Medicare.

You may receive Part D through:

Every Part D plan has its own formulary, which is the plan's list of covered medications.

Depending on the plan and medication, there may also be:

This is why prescription medications should be reviewed when comparing Medicare coverage.

A plan that works well for one person may not be appropriate for another person taking different medications.


What Is Original Medicare?

Original Medicare consists of Part A and Part B.

With Original Medicare, you generally may receive covered services from any doctor or hospital in the United States that accepts Medicare.

A person choosing Original Medicare may also consider:

Original Medicare by itself does not have an annual maximum out-of-pocket limit for Part A and Part B services.

That is one reason some beneficiaries with Original Medicare purchase a Medicare Supplement policy to help with certain Medicare cost-sharing expenses.


What Is Medicare Supplement Insurance, or Medigap?

Medicare Supplement Insurance, commonly called Medigap, is private insurance designed to work alongside Original Medicare.

Medigap can help pay certain out-of-pocket costs left by Original Medicare, such as:

depending on the standardized Medigap plan selected.

Medigap is not Medicare Advantage.

You generally cannot have both a Medicare Advantage plan and a Medigap policy at the same time.

One particularly important period is the six-month Medigap Open Enrollment Period.

Under federal rules, this period generally begins the first month in which you are:

During this period, insurers generally cannot use medical underwriting to deny your Medigap application because of pre-existing health conditions.

After this enrollment period ends, federal law may not guarantee your ability to purchase another Medigap policy unless you qualify for a specific guaranteed-issue right. State laws may provide additional protections.


The Two Main Ways to Receive Medicare Coverage

Once you have Medicare Part A and Part B, you generally have two primary coverage paths.

Option 1: Original Medicare

Typically:

Medicare Part A + Medicare Part B

You may then add:

Part D prescription drug coverage

and, if desired and eligible:

Medicare Supplement Insurance (Medigap)

Option 2: Medicare Advantage

You receive Medicare-covered Part A and Part B services through a:

Medicare Advantage plan: Part C

Most plans also include:

Part D prescription drug coverage

Neither route is automatically the correct answer for every beneficiary.

The appropriate choice depends on your individual healthcare needs, providers, prescriptions, finances, travel habits, risk tolerance, and coverage preferences.