What Is Medicare Advantage?
Medicare Advantage, also called Part C, lets you get Medicare coverage through a private insurance company instead of the federal government.
If you enroll in Medicare Advantage, you still use your Medicare benefits. But the insurance company manages your coverage, decides which doctors and hospitals are in-network, and sets how much they pay for your care.
Every Medicare Advantage plan must cover all services that Original Medicare Part A (hospital care) and Part B (doctor and outpatient visits) cover.
Most plans also include prescription drug coverage (Part D) with no extra premium. You still pay the plan's monthly premium if it charges one. Many plans add extras that Original Medicare doesn't offer: dental, vision, hearing aids, fitness programs, meal delivery, and rides to medical visits.
Network Models: HMO, PPO, and PFFS
Medicare Advantage plans use different network structures. The most common are:
- Health Maintenance Organization (HMO): You pick an in-network primary care doctor who coordinates your care and refers you to specialists. You can only see in-network providers except in emergencies. These plans have the lowest premiums but least flexibility.
- Preferred Provider Organization (PPO): You can see both in-network and out-of-network providers. Seeing out-of-network doctors costs more but requires no referral. You don't need to pick a primary care doctor. More flexibility means higher costs.
- Private Fee-For-Service (PFFS): The plan doesn't have to maintain a network. You can see any willing Medicare provider without a referral. The plan sets what it pays per visit. Rare, but offers maximum flexibility.
Referrals and Prior Authorization
Most Medicare Advantage plans, especially HMOs, require you to get a referral from your primary care doctor before seeing a specialist.
Before paying for certain treatments, expensive drugs, or procedures, your plan may require prior authorization. This means your doctor must ask the plan to approve the treatment as medically necessary before the plan will pay for it.
Original Medicare generally doesn't require referrals or prior authorization. This is a key difference. Delays can happen if the plan doesn't approve a procedure or drug right away. But plans have legally set timeframes for review decisions.
The Out-of-Pocket Maximum (MOOP)
Medicare Advantage has a major benefit: the Maximum Out-of-Pocket (MOOP) limit. This is an annual cap on how much you pay out of pocket for covered services. Once you hit this limit, the plan pays 100% of your covered care for the rest of the year.
Original Medicare has no spending cap. If you need expensive services all year—hospitalizations, surgery, skilled nursing care—your costs could be unlimited. Medicare Advantage's MOOP gives you a ceiling, which helps especially if you have chronic illnesses or use a lot of healthcare.
MOOP costs vary by plan and change each year. Check your specific plan's MOOP in its evidence of coverage or on Medicare.gov's plan-comparison tool.
How CMS Pays Medicare Advantage Plans
Original Medicare pays doctors and hospitals per service they provide. Medicare Advantage works differently.
CMS pays each plan a fixed monthly amount per member, no matter how much care that person uses. This is called a capitated payment (a set fee per person). The plan keeps money if members use less care. The plan loses money if members use more care.
This payment method encourages plans to keep members healthy and avoid unnecessary services. But critics say it can also pressure plans to deny needed care. To prevent this, CMS adjusts payments based on member risk factors (age, health status, chronic conditions) so plans aren't punished for enrolling sicker people.
Special Needs Plans (SNPs)
Some Medicare Advantage plans serve people with specific circumstances:
- Dual-Eligible SNPs (D-SNPs): For people who qualify for both Medicare and Medicaid (low-income). These plans coordinate benefits across both programs. See Dual-Eligible Coverage for details.
- Chronic Condition SNPs (C-SNPs): For people with specific chronic diseases like diabetes, COPD, or heart disease. Plans tailor benefits and case management to that condition.
- Institutional SNPs (I-SNPs): For people living in nursing homes or long-term care facilities. Benefits are designed for that setting.
SNPs often provide richer care coordination and services tailored to their population.
Quality Ratings: The Star System
CMS publishes Star Ratings for Medicare Advantage plans each fall. Ratings measure quality on: member satisfaction, care coordination, preventive care, management of chronic conditions, and timeliness of care. Plans get 1 to 5 stars.
Star Ratings help you compare plan quality, not just cost. Plans with consistently high stars usually have better member experiences. Plans earning 4 or more stars may start enrollment earlier in the year. See Understanding Star Ratings for full details.
Prescription Drug Coverage
Most Medicare Advantage plans include prescription drug coverage (Part D). Some charge a separate drug premium. Others bundle it into the plan premium.
Formularies (lists of covered drugs) and cost-sharing (copays and coinsurance, your share of a bill as a percentage) vary by plan.
If you enroll in Medicare Advantage with drug coverage, you cannot also enroll in a standalone Medigap or Medicaid plan. Learn more at Medicare Part D: Prescription Drug Coverage.
| Feature | Original Medicare | Medicare Advantage |
|---|---|---|
| Coverage | Parts A & B (hospital & doctor); drug coverage separate | Parts A & B bundled; most plans include Part D |
| Provider Network | Any Medicare-accepting provider nationwide | Usually limited to in-network; out-of-network costs higher or not covered |
| Referrals Required | No | Yes, for most HMO plans |
| Prior Authorization | Generally no | Often yes for specialists, procedures, expensive drugs |
| Out-of-Pocket Cap | None (unlimited) | Yes, set annually (varies by plan) |
| Extra Benefits | Not included | Often: dental, vision, hearing, fitness, meal delivery |
| Flexibility | High—see any provider anywhere | Limited—network rules apply; may require approval |
| Supplemental Insurance | Medigap available to fill gaps | Cannot enroll in Medigap while in Medicare Advantage |
Medicare Advantage vs. Original Medicare: Key Tradeoffs
Why People Choose Medicare Advantage
- Out-of-pocket ceiling: The MOOP protects you from catastrophic costs if you need a lot of care.
- Extra benefits: Dental, vision, hearing, and fitness perks can improve quality of life and reduce out-of-pocket spending.
- Care coordination: Many plans assign a case manager to coordinate your care. This helps especially if you have chronic conditions.
- Bundled drug coverage: No need to shop separately for Part D. Your prescriptions coordinate with medical coverage.
- Low or no premium: Many Medicare Advantage plans charge $0 monthly premiums. You still pay the Part B premium to Medicare.
Why People Choose Original Medicare
- Provider freedom: No network restrictions. See any Medicare-accepting doctor or specialist nationwide without a referral.
- No prior authorization: Doctors order tests and treatments. Medicare pays without plan approval needed in advance.
- Portability: Coverage follows you anywhere in the U.S. Plan changes don't affect your provider relationships.
- Supplement options: Medigap policies fill gaps in Original Medicare's cost-sharing. Combined with Medigap, costs are predictable.
- Stability: Original Medicare rules stay the same year to year. Medicare Advantage plans can change benefits, premiums, and networks annually.
Annual Changes and Enrollment
Medicare Advantage plans can change benefits, premiums, formularies, and networks every year. What you have this year may not be available next year.
The plan might leave your area, change networks, add higher copays, or drop benefits.
That's why you should review your coverage during the Annual Enrollment Period (AEP) each fall. Review even if you've been happy with your plan. See Enrollment & Deadlines for dates and rules.
Important Limitations
Medicare Advantage plans must cover what Original Medicare does. But they can charge higher cost-sharing (copays and coinsurance) for certain services.
For example, a plan might charge $200 per hospital visit or $50 per specialist visit. Original Medicare's cost-sharing is lower and standardized.
If you travel outside your plan's service area often or spend time outside the U.S., Medicare Advantage's network limits may frustrate you. Original Medicare covers you anywhere in the country and worldwide (in limited cases).
Getting Help Comparing and Choosing
Comparing Medicare Advantage plans is complex. Use these resources:
- Medicare.gov's plan-finder: Enter your zip code, current doctors, and drugs. You'll see available plans, costs, ratings, and quality scores.
- SHIP (State Health Insurance Assistance Program): Free, unbiased counseling from trained advisors in your state. Find yours at SHIP Directory.
- Plan documents: Every plan's evidence of coverage lists what's covered, copays, deductibles, prior authorization rules, and the formulary (list of covered drugs).
- Your current providers: Call your doctors and pharmacies to confirm they're in-network for plans you're considering.
See Choosing Coverage for a step-by-step comparison framework and Getting Help Paying for assistance with costs and premiums.
Related Topics
Want to learn more? Explore:
- Plan Types—overview of all Medicare coverage options
- Medicare Part D: Prescription Drug Coverage
- Dual-Eligible Coverage—Medicare + Medicaid coordination
- Understanding Star Ratings—how to use quality data when comparing plans
- Understanding Your Costs—deductibles, copays, and other out-of-pocket expenses