Medicare Advantage Managed Care vs. Medigap Insurance

A Medicare managed care plan is one way to get coverage for the health care bills that Medicare doesn't pay. Private insurance companies offer these Medicare managed care plans, which are called "Medicare Advantage plans" through what's known as "Part C" of Medicare. Enrollment in Medicare Advantage plans is increasing rapidly due to their low cost, and more than half of all Medicare recipients are enrolled in Medicare Advantage plans in 2025.

Medicare Advantage vs. Original Medicare

Medicare managed care plans are HMOs or PPOs that provide basic Medicare coverage plus other coverage to fill the gaps in Medicare coverage. Many Advantage plans have no monthly premiums, and some plans even provide a credit toward your Part B monthly premium that's taken out of your Social Security check.

With original Medicare, you usually pay 20% of the Medicare-approved amount for any service, with no yearly limit (after you meet the Part A or Part B deductible). With Medicare Advantage plans, you may have small copays for doctor visits, and slightly larger copays for hospital stays or outpatient procedures, but most other costs are covered, and there's a yearly limit on the amount you pay for out-of-pocket costs.

The main difference between Medicare and Medicare Advantage, besides the cost, is that Medicare Advantage plans generally require you to go through your primary care doctor to get referrals to specialists.

Medicare Managed Care Plans vs. Medigap Insurance

Medicare managed care plans fill the gaps in basic Medicare, as do Medigap policies. However, Medicare managed care plans and Medigap policies operate in different ways. Medigap insurance policies work alongside original Medicare to pay the bills: Medical bills are sent both to Medicare and to a Medigap insurer, and each pays a portion of the approved charges. Medigap policies require separate monthly premiums, which can be quite expensive. Medigap policies can deny enrollment or charge higher premiums based on age or pre-existing conditions.

Medicare managed care plans, on the other hand, provide all the coverage themselves, including all basic Medicare coverage, plus other coverage to fill the gaps in Medicare coverage. Medicare Advantage plans can provide benefits not covered by original Medicare, such as eyeglasses, hearing aids, dental coverage, over-the-counter medications, transportation to doctors' appointments, and membership to fitness centers.

With Medicare Advantage, the extent of coverage beyond Medicare, the size of premiums and copayments, and decisions about paying for treatment are all controlled by the managed care plan itself, not by Medicare. And Medicare Advantage plans can't deny enrollment to anyone based on age or pre-existing conditions.

What Is Managed Medicare?

The basic premise of managed Medicare is that the member-patient agrees to receive care only from specific doctors, hospitals, and others—called a network—in exchange for reduced overall healthcare costs. This makes Medicare Advantage plans cheaper overall than Medigap plans. But it can also be a negative of Medicare Advantage plans.

Some people decide to stick with original Medicare and add a costly Medigap policy so that they can avoid having to go to their primary care doctors to get referrals to see specialists and then waiting to get those referrals authorized.

Several varieties of Medicare managed care plans are available through Medicare Advantage. Some have narrow restrictions on consulting with specialists or seeing providers from outside the network. Others give members more freedom to choose when they see doctors and which doctors they may consult for treatment. Plans that offer more choices in coverage—especially PPOs and HMOs with point-of-service options—charge higher premiums.

Many Medicare Advantage plans cover prescription drugs (which would otherwise be provided by Medicare Part D), with the plan member paying various copays for the medications.

Here are the basic types of managed Medicare plans.

Medicare Health Maintenance Organizations (HMOs)

The HMO is the least expensive and most restrictive Medicare managed care plan. It's also by far the most common type of Medicare managed care plan. There are three main restrictions with a Medicare HMO plan.

Care within the network only. Each HMO maintains a list—called a network—of doctors and other healthcare providers. The HMO member must receive care only from a provider in the network, except in emergencies. If the plan member uses a provider from outside the network, the plan pays nothing toward the bill. (And Medicare won't pay any of the bill either, because the plan member has withdrawn from Original Medicare by joining managed care.)

You should be able to discuss with your doctors a particular Advantage plan you're considering. Ask whether your doctor has heard of problems with the plan, particularly with approval of treatments, referrals to specialists, or early release from inpatient hospital care.

All care through primary care physician. An HMO member must select a primary care physician from the plan's network and see this doctor first for most medical needs. An HMO member can only see other doctors or providers—even from within the plan's network—with a referral by the primary care physician. Even if you regularly see a variety of specialists, your primary care physician must usually refer you to those doctors. You can't simply make an appointment to see them on your own.

Prior HMO approval of some services. HMOs may require that your primary care physician or other network physician obtain prior approval from the plan for certain medical services the doctor may want to prescribe. If plan administrators don't believe a service is medically necessary, or believe service from a non-specialist or other less expensive treatment would do just as well, they can deny coverage for that prescribed service.

Medicare HMOs With Point-of-Service (POS) Option

A few HMOs have a significant wrinkle that makes them more attractive—and more expensive—than standard HMO plans. These plans offer what is called a point-of-service option. This option allows a member to see physicians and other providers who aren't in the HMO's network and to receive services from specialists without first going through a primary care physician (called "self-referring").

But when a member does go outside the network or sees a specialist directly, the plan pays a smaller part of the bill than if the member had followed regular HMO procedures. The member usually pays a higher premium for this plan than for a standard HMO plan, and a higher copayment each time the point-of-service option is used.

Medicare Preferred Provider Organizations (PPOs)

Although it has a different name, using a PPO works much the same as using an HMO's point-of-service option. PPOs still use a network of providers, and if a member receives a service from a PPO's network of providers, the cost to the member is lower than if the member sees a provider outside the network. (Unlike an HMO or an HMO with a point-of-service option, however, a PPO doesn't always require the patient to go through a primary care physician for referrals to specialists. PPO patients are usually allowed to self-refer to some specialists.)

Medicare Advantage PPOs tend to be more expensive than HMOs, charging both a monthly premium and a higher copayment for non-network services. However, many people find that the extra flexibility in choosing doctors is an important comfort to them, and therefore worth the extra money.

Medicare Provider Sponsored Organizations (PSOs)

The PSO is a group of medical providers—doctors, clinics, and a hospital—that skips the insurance company middleman and contracts directly with patients. As with an HMO, the member pays a premium as well as a copayment each time a service is used.

Some PSOs in urban areas are large conglomerations of doctors and hospitals that offer considerable choice in providers, but many PSOs are small networks of providers that contract through a particular employer or other large organization or that serve a rural area that has no HMO.

Medicare Special Needs Plans (SNPs)

Medicare special needs plans are designed for people with specific health conditions or circumstances. SNPs provide all the regular benefits of managed Medicare plans, but they customize their provider networks, drug coverage, and care coordination to take care of members with chronic illnesses. The types of SNPs available depend on your location and your health situation—for example, some plans are tailored for people with diabetes or for those who are eligible for both Medicare and Medicaid. Learn more about Medicare SNPs.

What Does Medicare Part C Cover?

Medicare Advantage Part C plans are required to match Medicare Part A coverage and Part B coverage, combined, with one exception: hospice care. If you or a family member has a terminal illness and opts for hospice care, Original Medicare Part A will provide that coverage, while the Medicare Advantage plan will continue to cover health care services that aren't related to the terminal illness.

The following table includes some of the services covered by Medicare Advantage, as well as by Original Medicare.

Signing Up for a Medicare Advantage Plan

Signing up for a Medicare Advantage plan is a straightforward process, but timing is key. There are specific time periods during which you can sign up for a Part C plan. When you can enroll depends on your age and whether you or your spouse are still working. For more information, see Nolo's article on Medicare enrollment periods and coverage start dates.

When you're considering a Medicare managed care plan, you'll need to decide whether any of the plans available in your area offer adequate care at an affordable cost—including the costs of copayments for doctor visits and prescription drugs. To see a comparison of managed care plans in your area, go to Medicare Advantage plan options at the medicare.gov website.

Once you've chosen a plan, you can enroll online at medicare.gov, by phone, or by submitting a paper application. Your coverage typically begins the first day of the month after your enrollment is processed.