Are Medicare Advantage Plans Bad for People with Cancer?

Medicare Advantage plans are a popular alternative to original Medicare. They’re offered by private insurance companies, and those companies contract with — and receive funding from — the federal Medicare program. The Advantage plans advertise heavily, with celebs you know and love in their commercials, and they usually offer some extra perks, like gym memberships. But they’ve never been great for people with cancer or other serious or chronic conditions.

They've long been known for their high out-of-pocket costs and for rejecting claims. And recently, things have gotten worse. For the 2026 plan year, several major insurers stopped offering Medicare Advantage plans in some parts of the country. Also, a number of hospital systems and cancer centers stopped accepting some or all Medicare Advantage plans.

If you're currently enrolled in a Medicare Advantage plan, you have until March 31 to either switch to a different Medicare Advantage plan or to original Medicare. Here’s why a Medicare Advantage plan (instead of original Medicare) might not be the best choice for you if you’ve had a breast cancer diagnosis.

If you’ve been diagnosed with breast cancer, you need care that is prompt and accessible. But if you have a Medicare Advantage plan, you and your doctors have to get prior authorization for lots of types of cancer-related care. With a prior authorization, the insurance company requires you and your doctors to ask for approval before it will cover a test, treatment, medicine, or other service — and will sometimes deny coverage for care that your doctor thinks is medically necessary. Medicare Advantage plans usually require prior authorization for imaging tests, radiation therapy, inpatient hospital stays, outpatient oncology services, certain types of chemotherapy, and many other types of cancer medicines. This prior authorization process can cause treatment delays, denials, and inferior cancer care as the insurance company dictates treatment timing and options. (The prior authorization burdens of Medicare Advantage plans were a major reason some cancer centers and hospitals recently stopped accepting them.)

With original Medicare, more care is covered without prior authorization. According to the health information nonprofit KFF, in 2024 Medicare Advantage insurers required providers to submit nearly 53 million prior authorization requests, which was more than 84 times the number of prior authorization requests submitted to original Medicare. And Medicare Advantage plans fully or partially denied 4.1 million of those requests.

Medicare Advantage plans may not allow enrollees to get their care at top cancer hospitals, because in some cases their networks don’t include them. For instance, KFF found that one in five Medicare Advantage plans don’t include an academic medical center in their network. And in areas with a top cancer center, two out of five plans didn’t include it in their network. Not being able to get care at a top cancer hospital may limit your options for getting the best and most up-to-date treatment and for participating in clinical trials. 

Unlike original Medicare, which is accepted by almost all doctors, Medicare Advantage plans have much more limited networks of providers. KFF research shows that in 2025, people enrolled in original Medicare had access to more than twice as many doctors in their area than people enrolled in Medicare Advantage. Medicare Advantage plans are also more likely to require referrals to see specialists, which can be another barrier to getting timely care.   

Medicare Advantage plans may draw you in with flashy marketing about their lower monthly premiums and special benefits not offered by original Medicare, like vision, hearing, and dental care, and even gym memberships. But people with Medicare Advantage plans who need cancer-related care often have higher overall out-of-pocket costs (in the form of higher copays, coinsurance, and other costs). A 2023 study found that Medicare Advantage enrollees with a history of cancer were more likely to report financial strain and have difficulty paying their medical bills compared to enrollees in original Medicare.

Once you’ve been enrolled in a Medicare Advantage plan, it can be hard to get — or switch back to — a Medigap (Medicare supplemental) plan. In most states, the private insurance companies that offer Medigap plans can deny you coverage or charge you higher premiums if you have a pre-existing condition, such as breast cancer, and haven’t had a Medigap plan for more than six months. (There are some exceptions to this, but the rules can be confusing.). If you enroll in original Medicare plus a Medigap plan when you first become eligible (and stick with that), you can avoid those uncertainties.   

Experts say that for most people who’ve had breast cancer, original Medicare plus a supplemental (Medigap) plan and a Medicare prescription drug plan offer better coverage than a Medicare Advantage plan. Given the current upheaval in the Medicare Advantage market (with many plans being phased out and fewer providers accepting the remaining ones), original Medicare may also be a more reliable option. That said, it’s not always easy to switch out of a Medicare Advantage plan, and it may even be the best option for you, depending on your situation.

To get free, unbiased help comparing your Medicare coverage options, contact your state’s SHIP (State Health Insurance Assistance Program), The Medicare Rights Center, or Triage Cancer. These organizations can also help you navigate the process and the rules related to switching from Medicare Advantage to original Medicare plus a Medigap plan and a Medicare prescription drug plan.