Medicare Advantage is not purely a government program, but it’s not purely private either. It’s a federally authorized alternative to Original Medicare in which private insurance companies deliver your Medicare benefits under strict government rules and with government funding. The federal government pays these private insurers a monthly amount for each person enrolled, sets the rules they must follow, and audits their finances. More than half of all Medicare beneficiaries now get their coverage this way.
How Government and Private Roles Split
Original Medicare (Parts A and B) is run directly by the federal government through the Centers for Medicare and Medicaid Services (CMS). The government processes claims, pays doctors and hospitals, and sets the terms of coverage. Medicare Advantage, also called Part C, works differently. CMS contracts with private insurance companies to handle all of that on the government’s behalf. You’re still in the Medicare program, but a private company manages your care, builds a provider network, and decides how to deliver your benefits within federal guidelines.
Think of it as outsourcing. The government writes the contract, sets the standards, and provides the money. The private insurer does the day-to-day work of running your health plan. Your Medicare Advantage card comes from a company like UnitedHealthcare, Humana, or Aetna, but the program itself exists because of federal law and federal dollars.
How the Government Pays Private Plans
Medicare Advantage plans receive a monthly payment per enrollee from the federal government. The amount is based on a benchmark that CMS calculates for each county, using what the government spends on similar beneficiaries in Original Medicare in that area as a reference point. In counties with the highest traditional Medicare spending, the benchmark is set at 95% of that spending. In moderate-cost counties, it ranges from 100% to 107.5%.
CMS adjusts these payments for each enrollee’s health status, so a plan covering someone with multiple chronic conditions receives more than one covering a relatively healthy person. The agency publishes updated payment rates every year. For 2026, CMS projected a 5.06% increase in payments to Medicare Advantage plans, totaling over $25 billion in additional funding.
What Private Plans Must Cover
Every Medicare Advantage plan is legally required to cover all medically necessary services that Original Medicare covers. That includes hospital stays, doctor visits, lab work, and other Part A and Part B services. Plans cannot offer less than Original Medicare in this regard.
Where they often go further is in extra benefits. Many Medicare Advantage plans bundle in prescription drug coverage (Part D), plus perks like dental, vision, hearing, and fitness programs that Original Medicare does not include. Most plans also include Part D, so you typically don’t need to join a separate drug plan.
The tradeoff is how you access that care. In Original Medicare, you can see any doctor or hospital in the country that accepts Medicare, usually without referrals or prior approval. Medicare Advantage plans may require you to use doctors within the plan’s network, get referrals before seeing a specialist, and obtain prior authorization before certain services or supplies are covered.
How the Government Regulates These Plans
Federal oversight of Medicare Advantage is extensive. Title 42 of the Code of Federal Regulations dedicates an entire section to the program, covering everything from what benefits plans must offer to how they handle complaints and appeals. CMS audits the financial records of at least one-third of all Medicare Advantage organizations every year, reviewing data on costs, utilization, and how bids were calculated.
The regulatory framework covers several key areas:
- Network adequacy: Plans must prove they have enough contracted doctors, specialists, and facilities so that at least 85 to 90 percent of enrolled beneficiaries can reach a provider within published time and distance standards, depending on whether they live in an urban or rural area.
- Quality ratings: Plans participate in a Star Rating system that measures performance on clinical outcomes, patient experience, and administrative efficiency. These ratings directly affect how much the government pays the plan.
- Out-of-pocket limits: The government caps how much you can be charged. In 2025, the maximum out-of-pocket limit for in-network services is $9,350, and $14,000 when out-of-network services are included. Original Medicare has no equivalent cap, which is one reason many people choose Advantage plans or buy supplemental coverage.
- Marketing and communications: CMS reviews and approves the materials plans use to advertise and communicate with enrollees.
- Sanctions: CMS can impose penalties, including civil money fines, on plans that violate the rules.
Why the Distinction Matters
Whether you think of Medicare Advantage as a “government program” depends on what you mean by the phrase. Your eligibility comes from the government. Your funding comes from the government. The rules come from the government. But the company issuing your plan, building your provider network, and approving or denying your claims is private. This matters in practical ways.
If a Medicare Advantage plan denies a service you believe should be covered, your appeal goes through the private insurer first, then through an independent review process established by federal regulation. If you’re in Original Medicare, the government handles it directly. The experience of being in the program, from which doctors you can see to how quickly a procedure gets approved, is shaped by the private company running your plan, within the boundaries the government sets.
How Many People Are Enrolled
As of February 2025, 34.4 million people were enrolled in Medicare Advantage, representing 55 percent of all eligible Medicare beneficiaries. That’s a significant shift from the program’s earlier years, when the vast majority of Medicare recipients stayed in Original Medicare. The growth reflects both the appeal of extra benefits like dental and vision coverage and the $0 premium plans that many insurers offer in competitive markets.
Only beneficiaries enrolled in both Part A and Part B of Original Medicare are eligible to join a Medicare Advantage plan. You still pay your Part B premium (and any additional premium the plan charges), and the government continues funding your coverage through its monthly payments to the insurer. If you leave a Medicare Advantage plan, you return to Original Medicare, which the government administers directly.