Medicare gives you one fork in the road and it comes before everything else: take your Part A and Part B benefits from the federal government, or hand them to a private insurer under Part C.
This guide compares those two as they stand alone. There is a third configuration, Original Medicare with a Medigap policy bolted on to close its cost-sharing gaps, and because that changes the money completely it gets its own page: see Medicare Advantage vs Medigap for the full premium-versus-exposure math. Everything below was verified on September 6, 2026 against CMS, Medicare.gov and KFF’s 2026 analyses.
Coverage and Access, Side by Side
| Original Medicare (Parts A + B) | Medicare Advantage (Part C) | |
|---|---|---|
| Who runs it | The federal government | A private insurer under contract with Medicare |
| Provider access | Any doctor or hospital in the U.S. that accepts Medicare | Generally the plan’s network only; HMOs usually cover nothing out of network except emergencies |
| Referrals | Not required | Commonly required in HMOs |
| Prior authorization | Rare | 99% of enrollees are in plans requiring it for some services |
| Annual out-of-pocket limit on Part A/B | None | Capped at $9,250 in-network for 2026; $5,421 average |
| Drug coverage | Buy a separate Part D plan | Included in 96% of individual plans |
| Dental, vision, hearing | Not covered (limited exceptions) | Offered to more than 95% of enrollees |
| Fitness benefit | No | Offered to 91% of enrollees |
| Coverage away from home | Nationwide | Local network; emergency care covered anywhere |
| Can you add Medigap | Yes | No |
| Can you be dropped from the network | No network exists | Providers can leave the network mid-year |
What Each One Covers
Original Medicare is two parts. Part A is hospital insurance: inpatient stays, skilled nursing facility care, hospice, inpatient rehab and some home health. Part B is medical insurance: physician services, outpatient care, durable medical equipment, home health and most preventive services. What it does not cover is a short and expensive list, including routine dental, eye exams for glasses, hearing aids and long-term custodial care. For that last one see does Medicare cover long-term care.
Medicare Advantage plans must cover everything Part A and Part B cover. The plan then adds benefits on top, funded largely by rebate dollars Medicare pays it. In 2026, per KFF’s analysis of the CMS Landscape and Benefit files, more than 99% of individual Advantage enrollees are in plans offering eye exams or eyeglasses, 98% dental, 95% hearing exams or aids, and 91% a fitness benefit.
The extras are real but the fine print matters. Dental benefits often mean cleanings only, and most carry an annual dollar cap that the plan can change each year. Our Medicare dental coverage guide walks through what those caps typically buy. Some extras also thinned out for 2026: over-the-counter allowances dropped to 68% of enrollees from 79%, meal benefits to 65% from 70%, and transportation to 22% from 28%.
Cost Structure, Not Premiums
Both routes start at the same place. The standard Part B premium is $202.90 a month in 2026 per the CMS fact sheet published November 14, 2025, and you owe it under either one. About a third of individual Advantage plans give back part of it as a Part B rebate, most often less than $10 a month.
After that the structures diverge:
Original Medicare charges the $1,736 Part A inpatient hospital deductible per benefit period, $434 a day for hospital days 61 through 90, $868 a day for lifetime reserve days, $217 a day for skilled nursing days 21 through 100, a $283 annual Part B deductible, and then 20% coinsurance on most Part B services. There is no annual ceiling on any of that. Medicare.gov says so directly: there is no yearly limit on what you pay out of pocket unless you have supplemental coverage or join an Advantage plan.
Medicare Advantage replaces most of that with fixed copays and a hard annual cap. For 2026, federal rules cap the limit at $9,250 for in-network services and $13,900 for in-network and out-of-network combined. Actual plans set lower limits: the enrollment-weighted average is $5,421 in-network and $9,825 combined. Three quarters of enrollees pay no plan premium beyond Part B, and the average across all enrollees is about $15 a month.
Drugs sit outside both caps and run on their own rules. In 2026 no Part D plan may have a deductible above $615, and your out-of-pocket spending on covered Part D drugs is capped at $2,100, after which catastrophic coverage pays the rest of the year. That cap applies whether the drug coverage comes through a standalone plan or is bundled into an Advantage plan. If a specific drug is still unaffordable under either route, manufacturer and nonprofit prescription assistance programs work the same way regardless of which side of this choice you land on.
Provider Access and Prior Authorization
This is where the two systems feel most different in daily life.
Under Original Medicare there is no network. Any provider anywhere in the country that accepts Medicare accepts you, and you do not need a referral to see a specialist. Prior authorization is rare.
Under Medicare Advantage, KFF reports that enrollees have access to about half the physicians available to traditional Medicare beneficiaries in the same area, on average, and that networks vary widely from county to county and plan to plan. More than six in ten individual enrollees with drug coverage are in HMOs, which generally cover in-network care only. PPOs cover out-of-network care at higher cost sharing, and carry a higher average premium ($18 a month versus $12 for HMOs in 2026).
Prior authorization is near-universal in Advantage: 99% of enrollees are in plans that require it for at least some services. It is concentrated on high-cost care, required for acute inpatient stays by plans covering 97% of enrollees, skilled nursing facility stays 95%, Part B drugs 94% and home health 90%, and it is rarely used for preventive services (6%).
Neither system is automatically better here. Prior authorization is a cost control that also produces denials and delays. No network means no gatekeeper and also no cap.
Enrollment Periods
You are not locked in forever, but the windows are specific.
- Initial Enrollment Period. Starts three months before you get Medicare and ends three months after. You can join any plan. You need both Part A and Part B to join an Advantage plan.
- Open Enrollment Period, October 15 to December 7. Switch from Original Medicare to Advantage or from Advantage back to Original Medicare, and join, drop or switch a Part D plan. Coverage starts January 1.
- Medicare Advantage Open Enrollment Period, January 1 to March 31. Only if you are already in an Advantage plan. Switch to a different Advantage plan or drop back to Original Medicare and pick up a standalone Part D plan.
- Special Enrollment Periods. Triggered by life events like moving, losing other coverage, getting Medicaid or qualifying for Extra Help.
Missing your first window has a price of its own. See the Medicare late enrollment penalty, which is permanent for both Part B and Part D.
One asymmetry to plan around: switching back to Original Medicare is easy, but buying a Medigap policy afterward may not be, because outside a guaranteed issue right an insurer can medically underwrite you. That is covered in the Medigap open enrollment period guide.
Who Each One Suits
Original Medicare suits people who want unrestricted provider choice, who travel or live in two states, who are being treated at a specific academic center, or who expect to add a Medigap policy to close the no-cap problem. Standing alone with no supplement, it is the riskier of the two in a catastrophic year.
Medicare Advantage suits people whose doctors are already in a strong local network, who want dental, vision, hearing and drug coverage in one card, who want a hard ceiling on medical spending, and who would rather pay copays than premiums.
If your income is limited, run that check before the coverage check. Medicare Savings Programs can pay the $202.90 Part B premium outright, and Extra Help can cut drug costs to a few dollars a fill. If you also have Medicaid, see Medicaid vs Medicare for how the two coordinate.
Bottom Line
Original Medicare buys access and predictability of rules but leaves the ceiling open. Medicare Advantage buys a ceiling and extra benefits but narrows who you can see and adds a permission step. The third option, Original Medicare plus a supplement, is the expensive middle that removes both problems, and the money on that trade is laid out in Medicare Advantage vs Medigap.