Original Medicare offers broad provider choice and lets you add Part D and Medigap. Medicare Advantage combines benefits through a private plan, usually includes drug coverage, and often uses provider networks.
Original Medicare and Medicare Advantage are two ways to receive Medicare benefits. Both require you to qualify for Part A, which helps cover inpatient hospital care, and Part B, which helps cover doctor visits and outpatient care. The main differences are which doctors you can see, how you get drug coverage, what you pay, and who manages your benefits.
Original Medicare
Original Medicare is run by the federal government and includes Part A and Part B.
You can generally:
- See any U.S. doctor or hospital that takes Medicare
- Visit specialists without a referral in most cases
- Add a stand-alone Part D drug plan
- Buy Medigap if eligible to help with certain out-of-pocket costs
Original Medicare does not have an annual out-of-pocket maximum. Without Medigap or other supplemental coverage, you may have large bills to pay.
Medicare Advantage
Medicare Advantage, or Part C, is offered by Medicare-approved private insurers. Plans provide Part A and Part B benefits and usually include Part D. Common plan types include Health Maintenance Organizations (HMOs) and Preferred Provider Organizations (PPOs).
Plans may:
- Use local or regional provider networks
- Require a referral to a specialist or approval before certain care, called prior authorization
- Charge different copayments for different services
- Offer extra dental, vision, hearing, fitness, or transportation benefits
All Medicare Advantage plans have an annual out-of-pocket limit for covered Part A and Part B services. You must continue paying the Part B premium, even if the plan advertises a $0 plan premium.
Coverage Combinations
Original Medicare alone: broad access to U.S. providers that take Medicare, no yearly limit on what you pay for Part A and Part B care, and no automatic outpatient drug plan.
Original Medicare with Part D and Medigap: separate premiums; Part D pays under its drug rules, while Medigap pays your share of medical costs according to its benefits. It does not remove every uncovered expense.
Medicare Advantage with Part D: one private plan manages your medical and drug benefits. The yearly limit for medical costs is separate from the limit for covered drug costs. Network and approval rules vary by plan.
Medicare Advantage without Part D: check how you will get drug coverage before choosing this option. Most HMO/PPO members cannot simply add a stand-alone Part D plan; doing so can end Advantage enrollment.
Medicare’s comparison explains these choices. Medical prior authorization is less common in Original Medicare, but there are exceptions. The WISeR model covers selected services in six states during 2026–2031, with review either before care or after care but before Medicare pays. This does not mean all care nationwide needs advance approval.
Compare a Routine Year With a Higher-Use Year
Here is an example using made-up figures, not plan quotes. The premiums shown are in addition to Part B.
Yearly costs | Coverage combination 1 | Coverage combination 2 |
|---|---|---|
Additional premiums | $1,800 | $0 |
Your share of medical bills in a routine year | $600 | $1,000 |
Total for that routine year | $2,400 | $1,000 |
Your share of medical bills in a year with more care | $1,200 | $5,000 |
Total for that year with more care | $3,000 | $5,000 |
Add Part B, drug costs, and uncovered services separately. Use the actual policy benefits and medical maximum; the example does not predict what either Medicare route costs.
Before choosing Advantage, investigate your ability to buy Medigap if you later return to Original Medicare. The fall enrollment period does not guarantee that you can buy Medigap.
How to Choose
Check:
- Every doctor, hospital, and pharmacy you want to use
- All prescriptions and dosage forms
- Total expected yearly costs, not only premiums
- Referral and authorization requirements
- Travel and second-home needs
- Medigap enrollment protections in your state
- Extra-benefit limits and participating providers
Plan benefits and networks can change each year. Review coverage during Medicare Open Enrollment even if you are satisfied.
Start with the care you expect to use and the clinicians you want to keep. Compare the entire coverage combination, then check whether the same arrangement still works in a year when you need more treatment.
Medicare policy sources last checked: October 8, 2026.