Disadvantages of Medicare Advantage

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The main disadvantages of Medicare Advantage are narrower provider networks, frequent prior authorization, referral requirements in many plans, extra benefits with low dollar caps, plans that can change every year, coverage tied to a local service area, and the loss of access to Medigap, which can be hard to get back later. None of these make Medicare Advantage a bad choice for everyone. They do mean that a plan with a $0 premium can cost you in access, paperwork and flexibility, especially if you get seriously ill, travel often or want to switch back to Original Medicare in a few years.

Medicare Advantage replaces how you get Medicare, not Medicare itself

A Medicare Advantage plan doesn’t take you off Medicare. You stay enrolled in Parts A and B, you keep paying your Part B premium (a small number of plans cover part or all of it), and the plan must cover everything Original Medicare covers. What changes is the delivery: a private company receives a payment from Medicare to manage your care and sets its own networks, copays, approval rules and extra benefits within federal limits.

Original Medicare, often called traditional Medicare, is Part A (hospital insurance) and Part B (medical insurance) run by the federal government. You can add a standalone Part D drug plan and a Medigap policy from private insurers. Medicare Advantage bundles Parts A and B, and usually Part D, into one plan, often with some dental, vision and hearing coverage.

Medicare Advantage has grown quickly. According to KFF, 54% of Medicare-eligible people were enrolled in it in 2024, up from 39% five years earlier.

Original Medicare vs. Medicare Advantage at a glance

The out-of-pocket cap is the clearest financial advantage of Medicare Advantage: once you reach the plan’s maximum out-of-pocket limit (MOOP), the plan pays 100% of covered services for the rest of the year. Because Original Medicare alone has no cap, many people pair it with a Medigap plan such as Plan G or Plan N, which usually costs more each month but leaves very little to pay at the point of care.

1. Prior authorization can delay or block care

Prior authorization means the insurer must approve a service, supply or drug before it will pay. Medicare Advantage plans commonly require it for expensive care such as inpatient hospital stays, skilled nursing facility stays, advanced imaging and chemotherapy. The stated goal is to prevent unnecessary spending. The cost to you is time: a doctor’s office has to submit the request, the plan reviews it, and treatment can wait in the meantime. If the plan denies the request, you can appeal, but the service may not be covered while the appeal is pending.

The difference in volume is large. KFF counted roughly 50 million prior authorization requests to Medicare Advantage plans in 2024, about two per enrollee. In traditional Medicare, the rate was roughly one to two per 100 beneficiaries.

Original Medicare does use prior authorization, but only for a limited set of categories, including some durable medical equipment, non-emergency ambulance transport, and certain hospital outpatient and ambulatory surgical center procedures. Most doctor visits, tests and hospital admissions need no advance approval from Medicare.

For someone in good health, prior authorization may rarely come up. For someone facing cancer treatment, a joint replacement or rehabilitation after a hospital stay, it is the disadvantage most likely to be felt.

2. You may need a referral to see a specialist

More than half of Medicare Advantage plans are health maintenance organization (HMO) plans. In an HMO, you typically pick a primary care physician and need a referral from that doctor before the plan will cover a visit to a cardiologist, dermatologist or other specialist.

In practice, that can mean two appointments instead of one: first the primary care visit to get the referral, then the specialist visit. If your primary care office is booked weeks out, the specialist appointment moves back too. People who already see several specialists regularly carry this cost most often.

3. Network restrictions limit your choice of doctors and hospitals

Original Medicare is accepted by most providers: CMS reported a 98% participation rate among physicians and practitioners for 2024.

Each Medicare Advantage insurer builds its own network, and those networks vary widely. KFF research found that some narrower networks include less than 30% of the physicians in a county. In rural areas, access problems can persist even when a plan’s network includes a large share of local physicians, simply because there are fewer doctors overall.

What happens when you go outside the network depends on the plan type:

• HMO plans generally don’t cover out-of-network providers. You pay the full cost.
• HMO point-of-service (HMO-POS) plans may cover some out-of-network care if you accept a higher copay or coinsurance.
• Preferred provider organization (PPO) plans cover out-of-network providers who accept Medicare for Part A and B services, but you pay more for that care.
• Medical savings account (MSA) plans cover care from any provider who accepts Medicare, but only up to the balance in your MSA account until you meet the plan deductible.

PPO enrollees face a specific cost risk with Part B drugs, the medications given in a doctor’s office or clinic, such as infusions. In network, plans generally can’t charge more than 20% coinsurance or an equivalent copay for these drugs. Out of network, there is no comparable per-service limit, although the plan’s out-of-pocket maximum still applies. A KFF study found that more than one-third of enrollees with out-of-network coverage faced cost sharing above 20% for out-of-network Part B drugs, often 30% to 50%.

4. Extra benefits often come with low limits

Advertising for Medicare Advantage tends to emphasize “free” dental, vision and hearing coverage. These benefits are real, but the dollar limits are often modest.

• Vision: In KFF’s analysis of 2021 benefits, the average annual vision coverage limit was $160, well below what a pair of prescription glasses often costs.
• Dental: Among enrollees offered more extensive dental coverage in 2021, more than half were in plans capped at $1,000 a year or less, and some were in plans capped at $500 or less.
• Major dental work: Coverage for root canals and dentures is less common than coverage for cleanings and exams, and it varies by plan.

An example shows how quickly a cap is reached. Suppose a hypothetical plan covers comprehensive dental care up to $1,000 a year and you need a crown that costs $1,400. The plan pays up to its cap, and you pay the remaining $400 plus any other dental work that year in full.

Original Medicare generally doesn’t cover routine dental, vision or hearing care at all, and Medigap doesn’t fill that gap either. If these services matter to you, compare a plan’s actual limits with the cost of buying separate dental or vision insurance alongside Original Medicare.

5. Plans can change every year, and networks can change midyear

Original Medicare has one national benefit structure for Parts A and B. Medicare Advantage is thousands of separate products. KFF counted 3,719 Medicare Advantage plans in 2025, with the average beneficiary able to choose among 42 in their area. Each has its own premium, deductible, copays, drug formulary, network and extra benefits. Most include Part D drug coverage, but some don’t.

The bigger problem is that the plan you choose isn’t fixed. Insurers can change premiums, copays, covered drugs, extra benefits and the out-of-pocket maximum from one year to the next. Some changes help enrollees. Others cut benefits: KFF found that 65% of Medicare Advantage plans offered meal benefits in 2025, down from 72% in 2024. An insurer can also discontinue a plan entirely, which forces you to choose another.

Your plan must send an Annual Notice of Change each fall explaining what will be different the following year. You can then switch during the Annual Enrollment Period, October 15 to December 7, or use the Medicare Advantage Open Enrollment Period, January 1 to March 31, to change to another Medicare Advantage plan or return to Original Medicare once.

Networks are less predictable. Plans can add or remove doctors and hospitals at any point in the year, not just at renewal. Medicare rules require plans to take steps intended to prevent interruptions in medically necessary care when providers leave, but a doctor you chose the plan for can still drop out of the network after you’ve enrolled.

6. Coverage is tied to your service area

Each Medicare Advantage plan has a service area, defined by state and county. Outside it, routine care generally isn’t covered. The exceptions are emergency care, urgent care and dialysis. A routine checkup, a planned procedure or ongoing treatment in another state will typically not be covered.

This matters for people who split the year between two homes, spend months visiting family, or are unsure where they’ll live in retirement. Some PPO plans offer broader out-of-network or travel coverage, but the terms are set by each plan.

If you move permanently out of your plan’s service area, you can be disenrolled. You then get a Special Enrollment Period to choose a Medicare Advantage plan in your new area or return to Original Medicare.

Neither Original Medicare nor Medicare Advantage generally covers care outside the country, but with Original Medicare you can buy a Medigap policy that pays for foreign travel emergency care, up to the policy’s limits.

7. You can’t use Medigap, and getting it later may not be possible

Medigap helps pay the deductibles, copays and 20% coinsurance that Original Medicare leaves to you, but it can’t be used with Medicare Advantage. In a Medicare Advantage plan you pay the plan’s cost sharing until you hit its out-of-pocket maximum.

On average, Medigap premiums are higher than Medicare Advantage premiums, though individual policies vary. In return, Medigap lets you use any provider that accepts Medicare and makes your costs more predictable. Standardized Medigap benefits stay the same for each plan letter, although some dollar amounts are adjusted.

The disadvantage that surprises people most comes when they try to leave Medicare Advantage. Your best chance to buy Medigap is your Medigap Open Enrollment Period, the six months that begin in the month you are 65 or older and enrolled in Part B. During that window, insurers can’t use medical underwriting: they can’t deny you, charge you more, or delay coverage because of pre-existing conditions.

After that window closes, switching from Medicare Advantage back to Original Medicare is easy, but adding a Medigap policy generally isn’t guaranteed. In most states, insurers can review your health history and deny coverage or charge a higher premium. Someone who developed a heart condition or cancer while in a Medicare Advantage plan could end up on Original Medicare with no supplement and no out-of-pocket cap.

Exceptions that can protect you

• Trial rights. If you joined a Medicare Advantage plan when you first became eligible for Medicare at 65 and leave within the first 12 months, you generally have a guaranteed right to buy a Medigap policy. If you dropped a Medigap policy to try Medicare Advantage for the first time, you can usually return to that policy, or a similar one if it’s no longer sold, within 12 months.
• Other guaranteed-issue situations. Federal law also gives guaranteed-issue rights in certain cases, such as when a plan leaves your area or you move out of its service area.
• State rules. Connecticut, New York, Massachusetts and Maine offer Medigap guaranteed-issue protections beyond the initial enrollment period, though the timing and available plans vary by state.

One more detail: if you return to Original Medicare from a Medicare Advantage plan that included drug coverage, you need to enroll in a standalone Part D plan. Going without creditable drug coverage for 63 days or more in a row can trigger a permanent late enrollment penalty.

When Medicare Advantage can still make sense

Medicare Advantage can still be a reasonable choice when:

• Your budget is tight. Many plans charge a $0 or low premium beyond Part B, and the out-of-pocket maximum puts a ceiling on a bad year that Original Medicare alone doesn’t.
• You can’t get or afford Medigap. If you’re past your Medigap open enrollment window and would face underwriting, Medicare Advantage offers a cap that Original Medicare without a supplement doesn’t.
• Your doctors, hospital and pharmacy are in the network. Narrow networks matter less if the providers you use are already in them.
• You stay close to home. Service area limits matter less if you rarely travel within the U.S.
• You qualify for a Special Needs Plan. These plans are designed for people with certain chronic conditions, people in institutions, or people eligible for both Medicare and Medicaid, and they coordinate care around those needs.

Original Medicare with Medigap tends to fit people who want any-doctor flexibility, travel or live in more than one state, expect significant medical care, and can afford the higher monthly premiums.

How to check a Medicare Advantage plan before you enroll

1. Confirm every provider. Check that your primary care doctor, specialists, preferred hospital and pharmacy are in network, and ask the providers themselves, since directories can be out of date.
2. Run your prescriptions through the formulary. Look at which tier each drug falls on and whether it requires prior authorization or step therapy.
3. Read the Evidence of Coverage. Find which services need prior authorization and whether specialists require referrals.
4. Look past the premium. Note the deductible, copays for hospital stays and specialists, and the out-of-pocket maximum for in-network and, for PPOs, combined in- and out-of-network care.
5. Check the extra benefit limits. Find the annual dollar caps for dental, vision and hearing, not just whether those benefits exist.
6. Think about the exit. Know whether you’re within a trial-right period and what Medigap rules apply in your state before you give up Original Medicare.

FAQs

The Bottom Line

These drawbacks weigh most on people who expect serious medical care, see several specialists, travel or split time between states, or may want Original Medicare later. Before enrolling, confirm every provider and drug, read the prior authorization rules and benefit caps, and know your Medigap rights. Leaving the Medigap open enrollment window behind can mean facing medical underwriting if you switch back.