Original Medicare vs. Medicare Advantage: How to Compare

When you first get Medicare, and during certain times each year, you choose how you get your coverage. Medicare describes two main paths: Original Medicare (Part A and Part B), usually paired with a separate drug plan and sometimes a Medigap policy, or a Medicare Advantage Plan (Part C) from a private company that bundles your coverage together.

Neither path is right for everyone. The better fit depends on your doctors, your health, how much you travel, your budget and your appetite for predictable costs versus lower premiums. This guide walks through the differences Medicare itself highlights and gives you a set of questions for comparing real options in your area. It does not recommend any plan, company or path.

This site is independent and not affiliated with Medicare, CMS or any insurer. It offers general information, not insurance, financial or medical advice. For personal guidance, contact your State Health Insurance Assistance Program (SHIP).

The two paths in brief

According to the Medicare & You 2027 handbook, Original Medicare lets you use any doctor or hospital in the U.S. that accepts Medicare. You can add a separate Medicare drug plan for Part D, and you can buy supplemental coverage such as Medigap, or use coverage from an employer, union or Medicaid, to help with costs Medicare doesn't pay.

The same handbook describes Medicare Advantage Plans as Medicare-approved plans from private companies that bundle Part A, Part B and usually Part D. It says these plans may require you to use network doctors, may require prior approval for certain services or drugs, and set a yearly limit on what you pay out of pocket for services covered under Part A and Part B. If you join one, you still have Medicare, but the plan provides most of your Part A and Part B coverage.

Doctors, hospitals and referrals

This is often the deciding factor.

• Original Medicare: Medicare.gov's 2026 comparison page says you can use any doctor or hospital that takes Medicare anywhere in the U.S., and in most cases you don't need a referral to see a specialist.
• Medicare Advantage: the same page says you may need to use providers in the plan's network and service area for non-emergency care, and you may need a referral to see a specialist. Some plans cover non-emergency care out of network, though it may cost more.

Networks can shift during the year. The 2027 handbook says providers can join or leave a plan's network at any time, and if that happens you usually can't change plans mid-year, though you can choose a new provider. If staying with particular doctors matters to you, ask them directly which plans they work with, and recheck every fall.

Costs and out-of-pocket protection

Costs work very differently on the two paths.

With Original Medicare, Medicare.gov (2026) says you usually pay 20% of the Medicare-approved amount for Part B services after you meet your deductible, and there is no yearly limit on what you pay out of pocket unless you have supplemental coverage such as Medigap or other insurance. You pay the Part B premium, plus separate premiums for a drug plan and any Medigap policy.

With Medicare Advantage, Medicare.gov (2026) says out-of-pocket costs vary by plan. Medicare.gov's 2026 comparison page also says you still pay the Part B premium and may also pay a plan premium, while some plans have a $0 premium and some help pay all or part of your Part B premium. Plans have a yearly limit on what you pay for covered services, which may differ for in-network and out-of-network care.

The 2027 handbook lists the factors that shape what you'd pay in a Medicare Advantage Plan: the premium, deductibles, the copayment or coinsurance for each service, how often you need care, whether you stay in network, any extra benefits, and the plan's yearly out-of-pocket limit. A plan with a low premium can still cost more than another plan if you use a lot of care, so compare total likely costs, not just premiums.

Coverage rules and extra benefits

Medicare.gov (2026) says Medicare Advantage Plans must cover all medically necessary services that Original Medicare covers, and many offer extra benefits Original Medicare doesn't, like some vision, hearing and dental services. The 2027 handbook adds that these extra benefits are generally limited, so check exactly what's covered before you join.

Prior authorization is a key difference. Medicare.gov (2026) says Original Medicare in most cases doesn't require prior approval to cover services or supplies, while a Medicare Advantage Plan may require approval before it covers certain services or supplies.

Drug coverage differs too. Most Medicare Advantage Plans include Part D. With Original Medicare, you add a separate drug plan. The 2027 handbook warns that if you join an HMO or PPO plan that doesn't include drug coverage, you generally can't add a separate drug plan.

Travel and living in more than one place

Medicare.gov (2026) says Original Medicare generally doesn't cover care outside the U.S., but some Medigap policies cover emergency care abroad. Medicare Advantage Plans generally don't cover care outside the U.S. either, though some offer emergency and urgent care abroad as an extra benefit. Within the U.S., Medicare.gov's 2026 joining guidance suggests checking whether a plan will cover you if you live in another state for part of the year.

How the choice affects later choices

The decision isn't permanent, but switching isn't always smooth. You can change paths during fall Open Enrollment or, if you're in a Medicare Advantage Plan, during the Medicare Advantage Open Enrollment Period. The bigger issue is Medigap. The 2027 handbook says you can't use Medigap to pay Medicare Advantage costs, and it is illegal for anyone to sell you a Medigap policy while you're in a Medicare Advantage Plan unless you're switching back to Original Medicare. If you later leave a Medicare Advantage Plan outside a protected situation, a Medigap insurer may be able to deny you or charge more based on your health. Our guide to Medigap basics and guaranteed issue rights explains the protections, including trial rights for first-time Medicare Advantage members.

If you have employer or retiree coverage, the 2027 handbook warns that joining a Medicare Advantage Plan could cause you to lose that coverage for yourself, your spouse and your dependents, and you may not be able to get it back. Talk to your benefits administrator first.

Questions to compare real options

Use these with the Medicare Plan Finder, plan documents and a SHIP counselor:

1. Are my doctors, specialists, hospitals and pharmacies covered, and on what terms?
2. What would I pay in a year with light care, and in a year with a hospital stay or serious illness?
3. Which services need prior authorization or referrals?
4. Are my prescriptions covered, and at what tier?
5. What happens when I travel or spend part of the year elsewhere?
6. If I choose Original Medicare, can I buy a Medigap policy now without health questions, and what will it cost over time?
7. Will this choice affect any employer, retiree, TRICARE or Medicaid coverage I have?

For example, imagine two hypothetical neighbors. One sees several specialists, travels between two states and values freedom to see any provider; the other has one primary care doctor nearby and wants lower monthly premiums. They could reasonably land on different paths after working through the same questions.

Beware of anyone who pushes one path hard. Medicare.gov's 2026 marketing rules page says agents can't steer you toward a particular plan or pressure you to join.

Key takeaways

• Original Medicare offers broad provider choice and few prior approvals but no yearly out-of-pocket limit unless you add coverage such as Medigap.
• Medicare Advantage bundles coverage, usually includes drugs and has a yearly out-of-pocket limit, but may use networks, referrals and prior authorization.
• Compare total likely yearly costs, not premiums alone.
• Switching from Medicare Advantage back to Original Medicare later may limit your Medigap options.
• Check with any employer or retiree plan before joining a Medicare Advantage Plan, and use a SHIP counselor for unbiased help.

Sources

• Medicare.gov (CMS), Compare Original Medicare & Medicare Advantage
• Centers for Medicare & Medicaid Services, Medicare & You 2027 (official handbook)
• Medicare.gov (CMS), Joining a plan
• Medicare.gov (CMS), Marketing rules for Medicare health & drug plans
• Medicare.gov (CMS), Learn How Medigap Works
• Medicare.gov (CMS), Get ready to buy (Medigap)