Medicare Advantage vs. Medicare Supplement: What to Know

First, understand what you are comparing

Medicare Advantage and Medicare Supplement insurance are different types of coverage. Medicare Advantage, also called Part C, is another way to receive Medicare Part A and Part B benefits through a Medicare-approved private plan. Most plans include Part D prescription drug coverage, and some offer extra benefits that Original Medicare does not cover.

Medicare Supplement insurance, also called Medigap, does not replace Original Medicare. It works alongside Original Medicare and helps pay some of the deductibles, copayments, and coinsurance for services that Original Medicare covers. A person using Medigap generally has Original Medicare Parts A and B and may add a separate Part D plan for prescriptions.

Medigap does not work with Medicare Advantage and cannot pay Medicare Advantage copayments, deductibles, or premiums. If you are considering a change between these paths, verify your enrollment and Medigap rights before acting.

Compare provider access and coverage rules

With Original Medicare, you can generally use any doctor or hospital in the United States that accepts Medicare. In most cases, you do not need a referral to see a specialist. A standard Medigap policy follows Original Medicare's coverage decisions; a Medicare SELECT policy may require certain providers for full supplemental benefits.

Medicare Advantage plans may use provider networks and service areas for non-emergency care. Depending on the plan type, going outside the network may cost more or may not be covered. Plans may also require referrals or prior authorization for certain services or supplies.

Before choosing either path, check the doctors, hospitals, specialists, pharmacies, and medical equipment suppliers that matter to you. Provider participation and plan networks can change, so verify current information directly.

Look at the full cost picture—not one premium

Everyone with either path generally continues to pay the Medicare Part B premium. With Medicare Advantage, you may also pay a plan premium and pay copayments, coinsurance, or deductibles as you use covered services. Medicare Advantage plans have a yearly out-of-pocket limit for covered Part A and Part B services, although the amount and in-network or out-of-network rules vary by plan.

With Original Medicare and Medigap, you pay the Medigap premium in addition to the Part B premium and any separate Part D premium. The Medigap policy may pay some of your share of Original Medicare costs, depending on the standardized plan benefits. Medigap premiums vary by company, policy, location, and pricing method and may increase over time.

A useful comparison includes the full year: monthly premiums, likely medical use, prescriptions, provider access, maximum exposure, and the value you place on predictable versus pay-as-you-use costs. A low premium alone does not establish the better fit.

Prescription drugs, extra benefits, and travel matter

Most Medicare Advantage plans include Part D prescription drug coverage. Formularies, pharmacy networks, drug tiers, prior authorization, and member costs vary by plan and can change each year. In most Medicare Advantage plan types, you cannot join a separate Part D plan; certain plan types have exceptions, so verify the rule before enrolling.

Medigap policies sold after 2005 do not include prescription drug coverage, so a person using Original Medicare and Medigap can consider a separate Part D plan. Medigap also generally does not cover routine dental, vision, hearing aids, glasses, long-term care, or private-duty nursing.

Travel needs deserve a separate check. Original Medicare generally provides access to Medicare-participating providers across the United States, while Medicare Advantage non-emergency coverage may depend on the plan's network and service area. Original Medicare generally does not cover care outside the United States, although some Medigap policies and some Medicare Advantage plans may offer limited foreign-travel emergency coverage.

Enrollment timing can affect future choices

The federal Medigap Open Enrollment Period lasts six months and begins the first month you have Medicare Part B and are 65 or older. During that period, an insurer generally cannot deny a Medigap policy because of pre-existing health problems. After that one-time period, you may face medical underwriting, a higher premium, or an inability to buy a policy unless a guaranteed-issue right or state protection applies.

Medicare Advantage enrollment and changes follow Medicare's election periods and special enrollment rules. Moving from Medicare Advantage back to Original Medicare does not always mean you can buy any Medigap policy you want. Before dropping coverage, verify the effective dates, prescription coverage, Medigap eligibility, and any trial or guaranteed-issue rights that apply to your situation.

Keep current coverage in force until replacement coverage is confirmed and you understand when the new coverage begins. Timing questions are personal, so check current Medicare and state rules before acting.

Do not drop a Medicare Advantage plan or Medigap policy based only on a preliminary comparison. Confirm eligibility, acceptance, effective dates, and drug coverage first.

Questions to bring to a Medicare review

A useful review begins with your life—not with a predetermined product. Bring current plan documents and a list of the providers, prescriptions, pharmacies, travel patterns, other coverage, and budget concerns that matter to you.

Ask how each option would work in an ordinary year and in a year with more medical care. Then verify the answer in the current plan documents, Medigap outline of coverage, Medicare information, and carrier materials before making a decision.

• Do my doctors, hospitals, specialists, and pharmacies participate?
• How are my prescriptions covered, and what restrictions apply?
• What premiums and out-of-pocket costs could I face during the year?
• Would referrals, prior authorization, or network rules affect my care?
• How would the coverage work when I travel or live in another area temporarily?
• If I change later, could health underwriting or enrollment timing limit my choices?