Original Medicare vs Medicare Advantage, the Main Differences

Last edited Oct 16, 2026 · 3 min read

Note This article is for general information only and is not financial, tax or legal advice. Rules and rates change; check the official sources linked below and talk to a qualified professional about your situation.

Once you have Medicare Part A and Part B, you choose between two main ways to get coverage: Original Medicare or a Medicare Advantage plan. Medicare.gov says the biggest differences are provider choice, how costs work, and whether prescription drug coverage is built in. Neither is better for everyone, and this page only lays out the official comparison.

1. The two paths

Original Medicare includes Part A (Hospital Insurance) and Part B (Medical Insurance). You pay for services as you get them: Medicare pays part of the cost and you pay your share. You can add Part D drug coverage.

Medicare Advantage (Part C) is a Medicare-approved plan from a private company that serves as an alternative to Original Medicare. It includes Part A and Part B, and most plans include Part D. Medicare.gov adds that in many cases you can only use doctors who are in the plan's network.

2. Side by side

Question	Original Medicare	Medicare Advantage
Which doctors?	Any doctor or hospital that takes Medicare, anywhere in the U.S.	Often plan network and service area for non-emergency care
Specialist referral?	In most cases not needed	May be needed
Prior approval?	In most cases not needed	May be needed for certain services
Yearly out-of-pocket limit?	None, unless you have supplemental coverage	Yes, for covered Medicare services
Drug coverage	Join a separate Part D plan	Most plans include it
Extra benefits (vision, hearing, dental)	Not generally covered	Many plans add some
Medigap	Can buy	Cannot buy
Care outside the U.S.	Generally not covered	Generally not covered

3. Cost differences

Under Original Medicare, for Part B-covered services you usually pay 20 percent of the Medicare-approved amount after you meet your deductible. You also pay a monthly Part B premium, and a separate premium if you join a drug plan.

With Medicare Advantage you still pay the Part B premium, and you may also pay the plan's premium. Medicare.gov notes that some plans have a $0 premium and may help pay all or part of the Part B premium. Out-of-pocket costs vary by service. Plans have a yearly limit on what you pay for covered Medicare services (which may differ for in-network and out-of-network care), and after you reach it you pay nothing for covered services for the rest of the year.

Original Medicare has no yearly limit unless you add other coverage.

4. What Medigap does

Medicare Supplement Insurance, called Medigap, is extra insurance from a private company that helps pay your share of costs in Original Medicare. Medicare.gov says policies are standardized, named in most states by letters such as Plan G or Plan K, and the benefits are the same no matter which company sells them. Price is the only difference. If you do not buy a Medigap policy within 6 months of when you first get Part A and Part B, you may not be able to buy one or may pay more. Generally, Medigap does not cover long-term care, vision, dental, hearing aids, private-duty nursing or prescription drugs.

If you choose Medicare Advantage, you cannot buy Medigap to cover its out-of-pocket costs.

5. When you can switch

You can only join, switch or drop a Medicare Advantage plan during certain enrollment periods. As of October 2026, Medicare.gov lists:

Initial Enrollment Period: generally when you turn 65. It lasts 7 months, starting 3 months before you turn 65 and ending 3 months after the month you turn 65.
Open Enrollment Period, October 15 to December 7: you can switch between Original Medicare and Medicare Advantage or change plans. Coverage starts January 1, and the plan must get your request by December 7.
Medicare Advantage Open Enrollment, January 1 to March 31: only if you are already in a Medicare Advantage plan. You can switch plans or return to Original Medicare.
Special Enrollment Periods: for situations such as moving or losing coverage.

6. Questions to answer before choosing

Medicare.gov suggests checking whether the plan covers your prescriptions, whether your doctors and pharmacies are in network, and what the premiums, deductibles and yearly cost estimates are. If you live in another state for part of the year, check whether the plan covers you there. If you have employer, union or other coverage, talk to the benefits administrator first.

7. Key takeaways

Original Medicare is Parts A and B with any Medicare-participating provider nationwide. Medicare Advantage bundles them through a private plan.
Medicare Advantage plans have a yearly out-of-pocket limit; Original Medicare has none without added coverage.
Medigap works only with Original Medicare.
Most Medicare Advantage plans include drug coverage; Original Medicare needs a separate Part D plan.
Plan changes are limited to set enrollment periods, including October 15 to December 7.

Sources

CategoriesRetirement, Plainlymedicaremedicare advantagehealth coverage