Medicare and Medicare Advantage both provide health coverage for people 65 and older (and some younger people with disabilities), but they work in fundamentally different ways. Original Medicare is run directly by the federal government, which pays your doctors and hospitals. Medicare Advantage is an alternative way to receive your Medicare benefits through a private insurance company, which gets a fixed payment from the government for your care and then manages your coverage, including networks, costs, and extra benefits. More than half of all Medicare beneficiaries, about 34.1 million people, now choose Medicare Advantage.
How Each One Is Structured
Original Medicare has two parts. Part A covers hospital stays, skilled nursing, and hospice care. Part B covers doctor visits, outpatient procedures, lab tests, and preventive services. You deal directly with the federal Medicare program, and the government pays claims to your providers. If you want prescription drug coverage, you buy a separate Part D plan from a private insurer.
Medicare Advantage (sometimes called Part C) bundles all of that into a single plan run by a private company like UnitedHealthcare, Humana, or Aetna. These plans must cover everything Original Medicare covers, but they can add benefits and structure costs differently. Most Medicare Advantage plans include built-in drug coverage, so you don’t need a separate Part D plan.
Choosing Your Doctors
This is one of the biggest practical differences. With Original Medicare, you can see any doctor, specialist, or hospital in the country that accepts Medicare, and the vast majority do. You don’t need a referral to see a specialist. You don’t need permission from Medicare before getting most services.
Medicare Advantage plans use provider networks, similar to employer-sponsored insurance. Most are structured as HMOs or PPOs. An HMO typically requires you to choose a primary care doctor and get referrals before seeing specialists. A PPO gives you more flexibility to see out-of-network providers, but you’ll pay more for it. Medicare Advantage plans also frequently require prior authorization to see specialists, get non-emergency hospital care, or receive certain treatments. With Original Medicare, prior authorization has historically been rare.
What Each Option Costs
Everyone on Medicare pays the standard Part B premium: $185 per month in 2025, with a $257 annual deductible. This applies whether you choose Original Medicare or Medicare Advantage, because Advantage plans are built on top of Parts A and B.
Many Medicare Advantage plans charge an additional monthly premium on top of the Part B premium, though a significant number advertise $0 extra premiums. In exchange, you’ll typically face copays and coinsurance when you use services, and your plan’s formulary determines what you pay for prescriptions.
With Original Medicare alone, you pay 20% of the Medicare-approved amount for most outpatient services after your deductible, with no cap on how much you could spend in a year. That unlimited exposure is why many people on Original Medicare buy a Medigap (Medicare Supplement) policy, which covers some or all of those cost-sharing gaps. Medigap premiums vary widely by plan type, location, and age, but they add a predictable monthly cost in exchange for financial protection.
Out-of-Pocket Limits
Original Medicare has no annual out-of-pocket maximum. If you have a serious illness or injury, your 20% coinsurance can add up without a ceiling, unless you carry Medigap coverage.
Medicare Advantage plans are required by federal law to cap your annual out-of-pocket spending. In 2025, that cap cannot exceed $9,350 for in-network services or $14,000 when combining in-network and out-of-network care. In practice, the average plan sets its in-network limit around $5,320. Once you hit your plan’s limit, the plan covers 100% of additional covered services for the rest of the year. This built-in protection is one of the strongest financial arguments for Medicare Advantage, especially if you don’t want to pay for a separate Medigap policy.
Dental, Vision, and Hearing Coverage
Original Medicare does not cover routine dental care, eye exams for glasses, or hearing aids, except in very limited circumstances. These are some of the most common healthcare expenses for older adults, and their absence from Original Medicare is a well-known gap.
Medicare Advantage plans routinely include dental, vision, and hearing benefits. About 97% of Medicare Advantage enrollees have access to hearing benefits, including both exams and hearing aids. Nearly two-thirds of enrollees with preventive dental coverage pay nothing out of pocket for cleanings, exams, and X-rays. More extensive dental work like fillings, extractions, and root canals typically requires 50% coinsurance. Some plans also offer fitness memberships, meal delivery after hospital stays, and transportation to medical appointments.
Prescription Drug Coverage
If you’re on Original Medicare and want drug coverage, you enroll in a standalone Part D plan sold by a private insurer. You pick a plan based on its formulary (the list of drugs it covers), its pharmacy network, and its premium. You can change your Part D plan every year during open enrollment.
Most Medicare Advantage plans bundle drug coverage directly into the plan. This simplifies things: one card, one premium, one insurer handling everything. The trade-off is that your drug formulary is tied to your overall plan, so switching to a plan with better drug coverage might also mean switching your doctor network.
Coverage When You Travel
Original Medicare works anywhere in the United States, including Puerto Rico, the U.S. Virgin Islands, Guam, and other territories. There are no network restrictions, so you can walk into any Medicare-accepting hospital or clinic in any state and be covered the same way.
Medicare Advantage plans are tied to a service area, which is usually a county or group of counties. If you travel or spend extended time outside that area, your coverage depends on your plan type. Some plans offer national pharmacy networks and broader coverage, while others impose higher costs or prior authorization requirements for out-of-area care. Both Original Medicare and Medicare Advantage are required to cover emergency and urgent care anywhere in the U.S. without extra restrictions.
There’s a practical limit for snowbirds and long-term travelers: many Medicare Advantage plans allow you to spend up to six consecutive months outside your service area before you risk being disenrolled. Some plans extend that to a full year. If you split your time between two states for large parts of the year, Original Medicare’s nationwide flexibility may be a better fit.
Medigap and Why It Matters
Medigap policies are sold by private insurers to fill the financial gaps in Original Medicare, covering things like the 20% coinsurance, hospital deductibles, and excess charges. They pair exclusively with Original Medicare. You cannot use a Medigap policy with a Medicare Advantage plan, because the Advantage plan replaces Original Medicare’s cost-sharing structure with its own.
This creates a key decision point. With Original Medicare plus Medigap plus a standalone Part D plan, you get maximum provider flexibility and predictable costs, but you’ll pay multiple premiums. With Medicare Advantage, you get a single plan with built-in protections and extra benefits, but you accept network restrictions and prior authorization requirements. Neither option is universally better. The right choice depends on how you use healthcare, where you live, which doctors you want to see, and how much you value simplicity versus flexibility.
Switching Between the Two
You can switch from Original Medicare to Medicare Advantage, or vice versa, during the annual open enrollment period from October 15 through December 7 each year. Medicare Advantage enrollees also get a separate window from January 1 through March 31 to switch to a different Advantage plan or drop back to Original Medicare.
One important caution: if you leave Original Medicare for a Medicare Advantage plan and later want to return, you may not be able to buy a Medigap policy at the same rates you would have gotten initially. In most states, Medigap insurers can charge higher premiums or deny coverage based on health conditions if you apply outside your initial enrollment period. This means the decision to try Medicare Advantage isn’t always easy to reverse without financial consequences.