Worst Medicare Advantage Plans: 7 Red Flags That Mean Your Parent's Plan Will Fail Them

Nobody writes this article. Insurance agents can't — their contracts with carriers prohibit them from publicly criticizing plans they're licensed to sell. Insurance brokerages won't — they make commissions from enrolling people in these plans. Medicare.gov doesn't — the government publishes star ratings but doesn't editorialize about which plans are bad.

That leaves you, the adult child, scrolling through Reddit at midnight trying to figure out if your parent's $0-premium Medicare Advantage plan is a good deal or a ticking time bomb. The posts are alarming: "MA is great until you get sick." "My mom's cancer treatment was delayed three weeks waiting for prior authorization." "The plan denied her rehabilitation stay after a hip replacement."

Those stories are real. But not all Medicare Advantage plans are bad, and blanket warnings aren't helpful when you need to evaluate a specific plan for your specific parent. What you need is a framework — a set of red flags that separate the good plans from the ones that will fail your parent when they need care the most.

Here are the seven warning signs.

Red Flag #1: The "$0 premium" is the entire sales pitch

A $0 monthly premium is real. It's not a scam. But it is not free healthcare.

Medicare Advantage plans make money because the federal government pays them a fixed amount per enrollee (called a "capitated payment"). The plan's profit depends on spending less on your parent's care than the government pays them. This creates a structural incentive to limit care — through networks, prior authorizations, and formulary restrictions — that doesn't exist in Original Medicare.

When the only thing an agent emphasizes is the $0 premium, they're hiding the costs that show up later:

• Hospital copays: Many $0-premium plans charge $300–$400/day for the first 5 days of a hospital stay. A 5-day hospitalization could cost $1,500–$2,000.
• Specialist copays: $40–$50 per specialist visit adds up quickly for seniors with multiple chronic conditions.
• Maximum out-of-pocket (MOOP): The MOOP for $0-premium plans can be as high as $7,550 (the 2026 CMS maximum for in-network costs). In a bad health year, your parent could owe this much — far more than they'd pay in a full year of Medigap premiums.

What to check: Look at the plan's Evidence of Coverage document (not the marketing brochure). Find the hospital copay, specialist copay, and maximum out-of-pocket limit. Add up what your parent would owe for a realistic bad-year scenario — a hospital stay, surgery, and 3 months of follow-up visits.

Red Flag #2: The plan is an HMO in a state your parent doesn't stay in year-round

HMO-style Medicare Advantage plans typically restrict coverage to a specific county or group of counties. If your parent lives in Maricopa County, Arizona for 8 months and visits grandchildren in Wisconsin for 4 months, the HMO will cover emergencies in Wisconsin but won't cover routine care, specialist visits, or prescriptions filled at an out-of-network pharmacy.

This is a critical issue for "snowbirds" — seniors who split their time between states. It's also an issue for parents who may need to move closer to adult children as they age.

What to check: Ask the plan, "What is covered if my parent needs non-emergency care outside the service area?" If the answer is "nothing" or "only urgent care," the plan is geographically fragile.

Red Flag #3: High prior authorization denial rates

Prior authorization means the insurance company must approve a treatment before the doctor can proceed. In theory, it prevents unnecessary procedures. In practice, it delays care — sometimes dangerously.

The HHS Office of Inspector General has reported that Medicare Advantage plans denied approximately 13% of prior authorization requests that should have been approved under Medicare coverage rules. Most beneficiaries never appealed these denials, meaning they either went without the treatment or paid out of pocket.

Not all plans are equal here. Some plans have prior authorization denial rates well above the industry average. CMS publishes plan-level data in its "Part C and D Performance Data" reports.

What to check: Look up the plan on Medicare.gov's Plan Finder. Check its CMS star rating (4+ stars is good; below 3 is concerning). Then search for the plan's name plus "prior authorization denial" to see if there are patterns of complaints.

Red Flag #4: The provider directory is outdated or misleading

Your parent's oncologist is "in-network" according to the plan's website. Your parent enrolls. Two months later, they discover the oncologist left the network in January. Or worse — the oncologist was never actually in-network, and the provider directory was simply wrong.

Inaccurate provider directories are a documented problem. A CMS study found that more than half of Medicare Advantage provider directories contained inaccurate information — listing providers who had left the network, moved, or were not accepting new patients.

What to check: Don't trust the online directory alone. Call your parent's specific doctors — primary care, cardiologist, oncologist, any specialist they see regularly — and ask each one directly: "Do you accept [Plan Name] Medicare Advantage? Are you currently in-network?" Verify this before enrollment, not after.

Red Flag #5: The plan has been sanctioned by CMS

CMS can impose sanctions on Medicare Advantage plans that violate federal rules — including enrollment freezes, civil monetary penalties, and suspension of marketing activities. A plan that has been sanctioned is a plan that CMS has found to be operating improperly.

Sanctions are publicly reported but rarely make the evening news. Most enrollees don't know their plan has been sanctioned unless they actively look it up.

What to check: Search for the plan's name on the CMS Enforcement Actions page. If the plan has a history of sanctions, that's a serious warning sign.

Red Flag #6: The plan's drug formulary doesn't cover your parent's medications

Medicare Advantage plans that include drug coverage (MA-PD) use formularies — approved drug lists organized into cost tiers. A medication your parent takes today might be on Tier 2 (moderate copay) with one plan and Tier 4 (high copay or step therapy required) with another. Or it might not be covered at all.

The danger is enrolling in a plan based on the premium and then discovering that your parent's $400/month medication isn't on the formulary — or requires a "step therapy" protocol where the plan forces your parent to try a cheaper drug first and fail on it before approving the prescribed medication.

What to check: Go to Medicare.gov's Plan Finder, enter your parent's zip code, add each of their current medications, and compare which plans cover them and at what tier. Do this every year during the Annual Enrollment Period — formularies change annually.

Red Flag #7: The plan's star rating is below 3 stars

CMS rates Medicare Advantage plans on a 1-to-5-star scale based on dozens of quality metrics: member satisfaction, preventive care, chronic disease management, customer service, complaints, and more.

A 4-star or 5-star plan has demonstrated consistent quality. A plan below 3 stars has documented problems — member complaints, care quality issues, or administrative failures that CMS has measured and scored.

Star ratings are imperfect — they don't capture every patient experience. But a plan that can't manage a 3-star rating on CMS's metrics is a plan with systemic problems, not one-off complaints.

What to check: Look up the plan's star rating on Medicare.gov. If it's below 3 stars, ask the agent why — and whether any of the low-scoring categories relate to your parent's specific needs (e.g., a plan scoring poorly on "managing chronic conditions" is especially risky for a parent with diabetes or heart disease).

How to use this framework

Not every Medicare Advantage plan is bad. Plans with 4+ star ratings, broad networks, transparent prior authorization policies, and low MOOPs serve millions of seniors well — particularly healthy seniors who value the convenience of bundled coverage and the $0 premium.

But the red flags above are specific, verifiable, and actionable. Before your parent enrolls in or renews any Medicare Advantage plan, run through all seven:

1. Is the $0 premium the main selling point, or does the agent discuss copays and MOOP?
2. Does the plan cover care outside your parent's home county?
3. What is the plan's prior authorization denial rate?
4. Have you verified each of your parent's doctors is in-network — by calling the doctor, not just checking the website?
5. Has the plan been sanctioned by CMS?
6. Are your parent's medications on the formulary, and at what tier?
7. Is the star rating 3 stars or above?

If any of these checks raises concerns, it doesn't necessarily mean your parent should avoid Advantage entirely — but it means you should investigate further before signing.

For a printable red flag checklist and a full Medigap vs. Medicare Advantage comparison worksheet, our Medicare Enrollment Guide gives you the tools to evaluate any plan against your parent's actual health needs, doctors, and prescriptions. No commissions, no agent referrals — just the framework for making the decision yourself.

This article is for educational purposes only. It does not recommend or discourage specific plans or carriers. For personalized Medicare counseling, contact your State Health Insurance Assistance Program (SHIP) or call 1-800-MEDICARE (1-800-633-4227). Prior authorization data from the HHS Office of Inspector General. Star ratings from CMS. All information reflects 2026 Medicare rules.