Medicare Advantage vs. Original Medicare: Which Is Right for You?

Two Ways to Get Medicare

When you enroll in Medicare, you face a fundamental choice: stick with Original Medicare (the government program) or switch to a Medicare Advantage plan (a private alternative). More than half of all Medicare beneficiaries now choose Medicare Advantage — in 2025, enrollment crossed 54% for the first time — but that does not mean it is the right choice for everyone.

The two paths offer genuinely different trade-offs. This guide walks you through each one so you can decide based on your own health needs, budget, and preferences — not a sales pitch.

Original Medicare: The Government Plan

Original Medicare is what most people think of when they hear "Medicare." It is administered directly by the federal government and consists of Part A (hospital insurance) and Part B (medical insurance).

The biggest advantage of Original Medicare is freedom. You can see any doctor, specialist, or hospital in the country that accepts Medicare — and the vast majority do. No referrals. No prior authorization. No networks to worry about.

What Original Medicare costs in 2025:

• Part B premium: $185.00 per month
• Part B deductible: $257 per year
• Part A hospital deductible: $1,676 per benefit period
• Coinsurance: 20% of the Medicare-approved amount for most Part B services — with no annual cap

That last point is critical. Original Medicare has no out-of-pocket maximum. If you have a $500,000 surgery, your 20% coinsurance is $100,000. There is no ceiling.

What Original Medicare does not cover:

• Routine dental, vision, and hearing services
• Most prescription drugs (you need a separate Part D plan)
• Long-term custodial care
• Most care outside the United States

Filling the gaps with Medigap

Most people on Original Medicare purchase a Medigap (Medicare Supplement) policy from a private insurer. Medigap pays the deductibles and coinsurance that Original Medicare does not cover — essentially creating the out-of-pocket protection that Original Medicare lacks on its own.

The most popular option is Plan G, which covers everything except the annual Part B deductible ($257 in 2025). The average Plan G premium at age 65 is approximately $143 per month, though this varies significantly by location and insurer. Plan N is a lower-cost alternative at around $112 per month, but it requires small copays for some office and ER visits.

With Medigap Plan G plus a Part D drug plan, the total monthly cost of Original Medicare in 2025 is roughly $358 to $378 — higher than most Medicare Advantage plans, but with significantly broader provider access and more predictable costs.

Medicare Advantage: The Private Plan Alternative

Medicare Advantage (Part C) is offered by private insurance companies like UnitedHealthcare, Humana, Aetna, and Blue Cross Blue Shield. When you enroll, the private plan replaces Original Medicare — you get your Part A and Part B benefits through the plan instead of the government. You still pay your Part B premium, but many plans charge no additional premium on top of that.

In 2025, 76% of Medicare Advantage enrollees pay $0 in plan premiums beyond their Part B premium. That is a significant monthly savings compared to Original Medicare plus Medigap.

What Medicare Advantage includes:

• Everything Original Medicare covers (except hospice, which stays under Part A)
• An annual out-of-pocket maximum (median: $5,400; CMS max: $9,350 in 2025)
• Most plans include Part D drug coverage
• Routine dental care (98% of plans)
• Vision coverage (99% of plans)
• Hearing coverage (98% of plans)
• Fitness programs, transportation, over-the-counter drug allowances, and telehealth (varies by plan)

The trade-offs:

Medicare Advantage plans use provider networks. Most are HMOs (which require referrals and limit you to in-network providers) or PPOs (which allow out-of-network care at higher cost). This is the fundamental trade-off: lower premiums and extra benefits in exchange for less flexibility in choosing your doctors.

How significant are the network restrictions? A 2025 KFF study found that Medicare Advantage enrollees have access to approximately 48% — roughly half — of the physicians in their area that are available to people on Original Medicare. Access to mental health providers is even more limited, with plans including less than 23% of psychiatrists in a county on average.

Prior authorization: the other trade-off

Medicare Advantage plans can require prior authorization — approval from the plan before you receive certain treatments, procedures, or medications. In 2024, MA insurers processed nearly 53 million prior authorization requests. Of those, 7.7% were denied.

An HHS Office of Inspector General report found that 13% of prior authorization denials actually met Medicare coverage rules — meaning those services would likely have been approved under Original Medicare. And when beneficiaries did appeal denials, 80.7% of those appeals were overturned. Original Medicare does not use prior authorization.

Side-by-Side Comparison

Here is how the two options stack up across the factors that matter most:

Monthly cost: Original Medicare with Medigap Plan G and Part D runs roughly $358-$378/month. Medicare Advantage is typically $185/month (just the Part B premium) for most enrollees.

Out-of-pocket maximum: Original Medicare has none. Medicare Advantage caps your annual costs — the median is $5,400, and the CMS maximum is $9,350 for in-network care.

Provider choice: Original Medicare lets you see any Medicare-accepting provider nationwide. Medicare Advantage limits you to roughly half the doctors in your area on average.

Referrals and prior authorization: None required with Original Medicare. Medicare Advantage HMO plans require referrals for specialists, and most plans use prior authorization for certain services.

Extra benefits: Original Medicare does not cover dental, vision, or hearing. Nearly all Medicare Advantage plans include these benefits.

Drug coverage: Original Medicare requires a separate Part D plan. Most Medicare Advantage plans include drug coverage. Both are now subject to the $2,000 annual out-of-pocket cap on prescriptions.

Travel: Original Medicare works anywhere in the U.S. Medicare Advantage plans typically cover only a local service area, though emergency and urgent care are covered nationwide.

When Original Medicare Makes More Sense

Original Medicare with a Medigap policy tends to be the better fit if:

• You want to see any doctor or specialist without restrictions
• You travel frequently or split time between states
• You have complex health conditions that require access to specialists or academic medical centers
• You want predictable, low out-of-pocket costs with no surprises
• You can afford the higher monthly premiums

When Medicare Advantage Makes More Sense

Medicare Advantage tends to be the better fit if:

• You want the lowest possible monthly premium
• You want dental, vision, and hearing coverage included in one plan
• You prefer having everything — medical, drugs, extras — in a single plan
• Your regular doctors are in the plan's network
• You mostly use local providers and do not need nationwide coverage
• You want an out-of-pocket maximum to protect against catastrophic costs

The Switching Trap You Need to Know About

This is arguably the most important thing in this entire article. You can switch between Original Medicare and Medicare Advantage, but the switch is not always equal in both directions.

Going from Original Medicare to Medicare Advantage is straightforward. You can enroll during the Annual Election Period (October 15 - December 7) with no health questions asked.

Going from Medicare Advantage back to Original Medicare is where it gets complicated. You can switch back during open enrollment, but if you want Medigap coverage, insurers in most states can use medical underwriting. That means if you have developed health conditions while on Medicare Advantage, you may be denied a Medigap policy — or charged significantly more for one.

There is one important protection: if you are trying Medicare Advantage for the first time, you have a 12-month trial right to return to Original Medicare and get your same Medigap policy back without medical underwriting. But if you have been on Medicare Advantage for years, that protection does not apply.

Some states — including New York, Connecticut, and Massachusetts — offer additional protections with annual Medigap open enrollment periods. But in most states, this switching limitation is real and can effectively lock you into Medicare Advantage if your health changes.

The Bottom Line

Neither option is universally better. Original Medicare with Medigap offers maximum flexibility and predictable costs but at a higher monthly premium. Medicare Advantage offers lower premiums and extra benefits but with network restrictions and prior authorization requirements.

The right choice depends on three things: your health, your doctors, and your budget. Before you decide, check whether your current doctors are in any Medicare Advantage plan you are considering, review the plan's formulary if you take prescription medications, and understand the prior authorization requirements for any treatments you may need.

And remember the switching trap — whichever path you choose at 65, understand that going back may not be as easy as going forward.