What is Medicare Advantage?

All Medicare Advantage plans are required to cover services that are covered by Medicare Part A and Medicare Part B (except hospice services, which are covered under Original Medicare for all beneficiaries).⁴ However, the out-of-pocket costs for these services vary widely between Original Medicare and Medicare Advantage. And there can be different coverage rules under Medicare Advantage plans, such as a requirement to use in-network medical providers or obtain prior authorization.

This differs from one Medicare Advantage plan to another, and also differs from Original Medicare. Original Medicare allows beneficiaries to use any provider who accepts Medicare, and prior authorization is very rarely used in Original Medicare.

Medicare Advantage enrollees only have one plan, rather than having to use multiple plans to get coverage for all the care they need. (Original Medicare does not have a cap on out-of-pocket costs and does not cover outpatient prescription drugs, so most Original Medicare enrollees rely on additional coverage, including Medigap plans and stand-alone Medicare Part D plans.)⁵

Since 2019, Medicare Advantage plans have been allowed to cover a broader range of extra benefits than they could in prior years4 and some Medicare Advantage plans have chosen to offer these benefits. As of 2025, 99% of Medicare Advantage plans offer some type of extra benefit not covered by Original Medicare⁶ (in some plans, different benefits are available to different enrollees depending on availability and health status.⁷

Medicare Open Enrollment – also known as the Annual Election Period – runs from October 15 to December 7 each year. This is an opportunity for Medicare beneficiaries to switch to a different Medicare Advantage plan or enroll in one for the first time. Plan selections made during this window will take effect January 1 of the following year.

Read our Guide to Medicare Open Enrollment.

In addition, a Medicare Advantage Open Enrollment Period – from January 1 through March 31 – is an opportunity for people already enrolled in Medicare Advantage to switch to another Medicare Advantage plan or to switch to Original Medicare.⁸

Read our overview of the Medicare Advantage Open Enrollment Period.

The cost of a Medicare Advantage plan varies depending on the plan you select. Medicare Advantage enrollees pay the Medicare Part B premium ($185/month for most beneficiaries in 2025),⁹ although some Medicare Advantage plans cover a portion of this cost for their enrollees.

Across all Medicare Advantage plans with integrated Part D coverage (MA-PDs), the average premium (in addition to the Medicare Part B premium) is $13.32/month in 2025, and it’s projected to decrease to $11.50/month in 2026.¹⁰ But more than three-quarters of MA-PD enrollees pay no premium in 2025, other than the premium for Part B. In other words, they’re in “zero premium” plans.⁶ These plans don’t charge a monthly premium and enrollees only have to pay the premium for Medicare Part B.

Average MA-PD premiums tend to be lower for HMOs versus PPOs. In 2025, KFF reported that the average HMO MA-PD had a premium of $11/month, whereas the average local PPO had a premium of $15/month and the average regional PPO (which represents a very small share of enrollment) had a premium of $75/month.⁶

The majority (54%) of 2025 Medicare Advantage enrollees are in HMOs. Local PPOs account for 45% of enrollees in 2025. Regional PPOs are rare, accounting for just 1% of enrollees in 2025.⁶

If you already have Medicare Part A and Medicare Part B (or are eligible to enroll in them), you can choose to enroll in any Medicare Advantage plan available in your area, instead of Original Medicare. You can do this when you’re first eligible for Medicare, or during Medicare Open Enrollment (the Annual Election Period).

But there are some rural areas of the country where no Medicare Advantage plans are available for purchase.¹¹ If you’re in one of those areas, Original Medicare is your only Medicare coverage option.

An increasing number of employers are using Medicare Advantage plans to provide health coverage to their retirees: About 17% of Medicare Advantage enrollees are enrolled in employer-sponsored Medicare Advantage plans.¹²

If you have employer-sponsored or union-sponsored health benefits, you may be able to add a Medicare Advantage plan, but you’ll want to discuss this with your benefits administrator first, to ensure that you won’t lose your existing health benefits if you enroll in a Medicare Advantage plan.

Special Needs Plans (SNPs) are Medicare Advantage plans that are specifically designed to cater to the needs of certain populations, such as individuals with certain chronic medical conditions. Institutional Special Needs Plans (I-SNPs) are for, among other things, people who live in long-term care skilled nursing facilities. In order to join any SNP, you would have to meet the specific eligibility requirements of the plan.¹³

There are five different types of Medicare Advantage plans¹⁴ although not all of them are available in all areas:

• HMO (health maintenance organization; some HMOs have a point-of-service option for out-of-network care, and are known as HMO-POS plans)
• PPO (preferred provider organization)
• PFFS (private fee-for-service)
• MSA (Medicare medical savings account)
• SNP (special needs plan; only available to enrollees who meet the plan’s special needs criteria; note that SNPs are also either PPO, HMO, or HMO-POS plans)

A few points to know about the different coverage types:

• If you enroll in an SNP or HMO (including an HMO-POS), you’ll need to select a primary care doctor. This is not required with an MSA, a PPO, or a PFFS¹⁴
• HMOs and SNPs may require a referral before seeing a specialist for certain services.¹⁴
• HMOs require enrollees to receive care from medical providers in the HMO’s network. (If it’s an HMO-POS, you might be able to get some care outside the network, albeit with higher out-of-pocket costs.)¹⁴
• About 96% of Medicare Advantage enrollees in 2025 were in plans that included Medicare Part D prescription drug coverage (MA-PDs).⁶
• If you need prescription drug coverage (and don’t already have it from another source, like an employer-sponsored plan) and you’re choosing an HMO or PPO Medicare Advantage plan, it’s important to select a plan that includes prescription drug coverage because you can’t purchase a stand-alone Medicare Part D prescription drug plan if you have an HMO or PPO Medicare Advantage plan.¹⁴
• SNP doesn’t describe a type of plan management. So SNPs are also either PPO, HMO, or HMO-POS plans, depending on their managed care approach.¹⁵
• SNPs are required to cover prescriptions.¹⁶
• PFFS plans sometimes cover prescriptions, but if you have one that doesn’t, you can supplement it with a stand-alone Medicare Part D prescription drug plan.¹⁷
• MSAs do not include prescription coverage, but you can buy a stand-alone Medicare Part D prescription drug plan to supplement your MSA plan.¹⁸

Yes, zero-premium Medicare Advantage plans are possible. But most enrollees do still have to pay the premium for Medicare Part B. (In 2025, the standard premium for Medicare Part B is $185/month.)⁹

As of 2025, 76% of all MA-PD enrollees only had to pay the Medicare Part B premium, as their plans did not have any additional premiums.⁶

Some Medicare Advantage plans pay some or all of the Part B premium on behalf of their enrollees, further reducing the monthly cost of the coverage.

People who are eligible for full Medicaid coverage (in addition to Medicare) do not have to pay Part B premiums¹⁹ And people who are eligible for a Medicare Savings Program may find that one of the programs covers the cost of Part B for them.²⁰