The Difference Between Medicare and Medicare Advantage

[Last updated September 5, 2025]

Navigating the complexities of Medicare is a significant challenge for many seniors and individuals with disabilities. The choices can be overwhelming, especially when deciding between original Medicare and a Medicare Advantage plan. This guide offers a clear and comprehensive comparison to help you make an informed decision.

What is original Medicare?

Original Medicare is a federally administered health insurance program for individuals 65 and older, as well as some younger people with specific disabilities. It is composed of two main parts:

• Part A (hospital insurance) covers inpatient hospital stays, short-term rehabilitation in a skilled nursing facility and/or intermittent home health care after a qualifying hospital stay, and hospice care for qualifying individuals. Most people don’t pay a premium for Part A if they or their spouse worked and paid Medicare taxes for at least 10 years.
• Part B (medical insurance) covers medically necessary services (such as doctor visits and outpatient care) and preventive services. The required Part B monthly premium for most people is $185 in 2025, but it can be higher for people with higher income.

Many people enroll in additional optional plans:

• Medigap (Medicare Supplement Insurance) plans are private insurance plans that help cover part or all of the 20% of costs not covered by original Medicare (such as copayments, coinsurance, and deductibles). 
• Part D (prescription drug coverage) plans are separate, optional plans purchased from private insurers to help cover the cost of prescription drugs.

What is Medicare Advantage?

Medicare Advantage (also known as Medicare Part C) is an alternative to original Medicare. Medicare-approved private insurance companies offer these plans. They must cover all the same services as original Medicare Parts A and B but often include extra benefits like prescription drug, dental, vision, and hearing coverage.

With a Medicare Advantage plan, you get all your Medicare coverage from a single plan provided by the private insurer. Medicare pays a fixed amount to the company each month to cover your care. Many plans have a $0 premium, but you will still pay the required Part B premium, as well as copayments, coinsurance, and an annual deductible. You cannot add a Medigap plan to cover these costs.

Similarities between original Medicare and Medicare Advantage

Despite differences, original Medicare and Medicare Advantage plans share many similarities, including eligibility requirements and certain covered services. Let’s look closer at their similarities.

Eligibility for original Medicare and Medicare Advantage

Eligibility requirements are the same for both original Medicare and Medicare Advantage. You must be a U.S. citizen or a permanent legal resident who has lived in the U.S. for at least five continuous years. You must also be at least one of the following:

• Age 65 or older.
• Under 65 with a qualifying disability, having received Social Security Disability Insurance (SSDI) benefits for 24 months.
• Diagnosed with end-stage renal disease (ESRD) or amyotrophic lateral sclerosis (ALS).

One difference to be aware of is that you must reside in a specific Medicare Advantage plan’s service area to be eligible for it.

Services covered by original Medicare and Medicare Advantage

All Medicare Advantage plans are legally required to provide the same services as original Medicare, including:

• Inpatient hospital care and skilled nursing facility care.
• Doctor visits and other medically necessary services.
• Preventive health care (e.g., screenings and vaccines).
• Durable medical equipment (DME).
• Ambulance services.
• Mental health services.

Services not covered by either original Medicare or Medicare Advantage

Neither program typically covers: 

• Long-term care in assisted living or a nursing home. It may cover short-term rehabilitation in a skilled nursing facility in specific situations.
• Custodial care (nonmedical assistance with daily activities like bathing, dressing, and eating), except when prescribed alongside home health care as being medically necessary, and then only for a limited time.
• Travel health insurance for care outside the U.S., though some Medigap and Medicare Advantage plans offer limited emergency coverage abroad.

Differences between original Medicare and Medicare Advantage  

It’s critical to understand the differences between original Medicare and Medicare Advantage when comparing them because changing from Medicare Advantage to original Medicare can be challenging.

How you access care

Access is one of the most critical distinctions between the two options. The choice you make determines your freedom to choose doctors and hospitals. 

• Original Medicare: You can see any doctor, specialist, or hospital in the U.S. that accepts Medicare. This feature offers maximum flexibility and is ideal for frequent travelers within the country. Referrals are rarely required to see a specialist, and prior authorizations are typically not necessary. (However, in 2026, prior authorizations for 17 specific services and procedures are being tested in six states.) 
• Medicare Advantage: Most Medicare Advantage plans operate similarly to managed care plans, such as health maintenance organizations (HMOs) and preferred provider organizations (PPOs), meaning you will typically be more limited in your health care providers.
  • HMOs typically require you to select a primary care physician (PCP) within the plan’s network and to obtain a referral each time you see a specialist. Care received outside the plan’s network of doctors and hospitals is typically not covered, except in cases of emergency medical treatment.
  • PPOs offer more flexibility. You don’t need a referral to see a specialist, and you can see out-of-network doctors, but at a higher cost.

Cost and premiums

The two programs’ financial structures differ significantly, affecting your fixed monthly cost and out-of-pocket expenses. Most costs will increase each year. 

• Original Medicare with Medigap and Part D: This option involves multiple premiums. 
  • Part A: This coverage is free for most people.
  • Part B: This monthly premium is a standardized amount for most people; however, it will be more expensive for those with higher incomes. The base Part B premium is projected at $206.50 for 2026, up from $185 in 2025.
  • Medigap and Part D: Separate monthly premiums vary based on the plan, the insurer, and your location. You may pay a higher total monthly premium, but these plans significantly lower your out-of-pocket expenses. You can see some plan prices by entering your zip code at the Medicare website. Monthly premiums for Medigap in 2025 range from $100 to $300 and average around $39 nationwide for Part D. The maximum out-of-pocket expense for prescription drugs under Part D is capped at $2,100 for 2026.
• Medicare Advantage: Premiums are generally simpler, but the out-of-pocket costs can be higher.
  • You continue to pay your Part B premium.
  • Your plan is likely to have a $0 premium.
  • Out-of-pocket expenses for services, such as copayments for doctor visits or hospital stays, can be higher than those under original Medicare with a Medigap plan. Most plans, however, have an annual out-of-pocket maximum, which is a key protection not found in original Medicare alone.

Coverage

While both programs must cover the same basic services, Medicare Advantage plans almost always offer additional benefits. 

• Original Medicare primarily focuses on hospital and medical care. To get prescription drug coverage, you must enroll in a separate Part D plan.
• Medicare Advantage covers everything original Medicare does, and many plans also offer valuable extra benefits, such as:
  • Prescription drug coverage built into the plan.
  • Routine dental, vision, and hearing exams.
  • Fitness programs like SilverSneakers.
  • Over-the-counter (OTC) allowances for health-related items.
  • Transportation to medical appointments.
  • Home-delivered meals under certain conditions.

Enrollment and switching plans

Regardless of which program you choose, it’s critical to understand the rules for enrolling in and switching between them and their plans.

Your initial enrollment period (IEP) is a seven-month window of the three months before the month you turn 65, your birth month, and the three months following. The IEP is when you can first enroll in either original Medicare or a Medicare Advantage plan.

After that, you will have regular enrollment periods during which you can switch programs and plans, usually without incurring any penalties. The one exception is for Medigap. If you switch from Medicare Advantage back to original Medicare after your IEP, with few exceptions, you’ll have to go through medical underwriting to get a Medigap policy. With underwriting, an insurer can ask you about existing health conditions and can deny you coverage or charge a higher premium based on your health history. This significant risk is just one reason why the right initial decision is so crucial.

In summary

Plan	Original Medicare	Medicare Advantage
Premiums	You pay a Part B premium and separate premiums for Medigap and Part D plans.	You pay the Part B premium, and many plans have a $0 or low monthly premium.
Doctor network	You can see any doctor or hospital that accepts Medicare nationwide.	You must use a network of providers (HMO, PPO). Going out of network costs more or isn’t covered.
Extra benefits	Covers hospital and medical services; no extra benefits.	Often also includes dental, vision, hearing, and prescription drugs in a single plan.
Referrals	Generally, no referral is needed to see a specialist.	HMO plans often require a referral to see a specialist. PPOs do not.
Out-of-pocket costs	No out-of-pocket maximum. Medigap helps cover deductibles and copays.	Has an annual out-of-pocket maximum to limit your spending.

Medicare vs. Medicare Advantage: Which is right for you?

There is no one right choice for everyone when deciding between original Medicare and a Medicare Advantage plan. Take time to compare original Medicare and Medicare Advantage to make the right choice for your situation. With the correct information, you can select the plan that best meets your health care needs.