Medicare Advantage vs. Medicare Supplement

Original Medicare and the gaps

Medicare is federal health insurance, mainly for people 65 and older and for some younger people with qualifying disabilities. Original Medicare is two pieces:

• Part A (hospital insurance). Inpatient hospital, some skilled nursing after a qualifying hospital stay, hospice, and some home health. Part A uses benefit periods and a deductible; it is not a simple monthly-cap system.
• Part B (medical insurance). Doctor visits, outpatient care, preventive services, and durable medical equipment. After a yearly deductible, Part B typically pays 80% of the Medicare-approved amount for many services. You pay the other 20%.

Two gaps matter for this comparison.

First, Original Medicare does not have an annual out-of-pocket maximum on that 20%. A year with a lot of outpatient care can mean a lot of coinsurance. There is no built-in stop-loss the way there is on many private plans.

Second, Original Medicare does not include most outpatient prescription drugs. That coverage is Part D, a separate benefit you add, or it is bundled inside many Medicare Advantage plans.

Original Medicare also does not cover most routine dental, hearing aids, eyeglasses, or long-term custodial care. Neither Medicare Advantage extras nor a Medicare Supplement policy is a substitute for a long-term care plan. The official list lives on Medicare.gov.

You generally pay a Part B premium as long as you have Part B, whether you stay on Original Medicare or join a Medicare Advantage plan. People with higher incomes may pay an extra amount (an income-related monthly adjustment amount). Figures change every year; Medicare.gov and Social Security publish the current ones.

Path one: Medicare Supplement plus Part D

A Medicare Supplement is a standardized private policy that sits on top of Original Medicare. Original Medicare still pays first. Medicare Supplement pays many of the leftover deductibles and coinsurance, depending on the plan letter you buy.

In most states, Medicare Supplement policies are standardized by letter (Plan A, Plan B, Plan D, Plan G, Plan K, Plan L, Plan M, Plan N, and a few others). Same letter, same core benefits, across companies — price, customer service, and extras around the edges can differ. Plan C and Plan F are not sold to people who became new to Medicare on or after January 1, 2020. People shopping today most often compare Plan G (broad coverage of Part A and Part B cost sharing, including Part B excess charges) and Plan N (lower premium, some copays, and it does not cover Part B excess charges). This page is not a ranking of letters. Medicare.gov has the benefit chart.

Medicare Supplement does not include Part D. You usually buy a separate Part D prescription drug plan and check the formulary (the list of covered drugs) and pharmacies the same way you would for any drug plan.

Doctors: if a provider accepts Medicare, you can generally use that provider. Referrals are not a Medicare Supplement feature. Prior authorization is not how Medicare Supplement works, because Medicare Supplement is following Original Medicare’s payment rules, not a private network’s rules.

The trade is premium. You pay Part B, plus the Medicare Supplement premium, plus Part D. Bills at the doctor’s office are more predictable. The monthly total is often higher than a low-premium Medicare Advantage plan. Whether that is “more expensive” depends on how much care you use — which is why listing doctors and drugs matters more than picking a slogan.

Massachusetts, Minnesota, and Wisconsin use different Medicare Supplement standardization. If you live in one of those states, use the Medicare.gov pages for that state rather than the letter chart above.

Path two: Medicare Advantage

Medicare Advantage is a private plan that replaces Original Medicare for your Part A and Part B benefits. You stay in Medicare. You agree to get those benefits through the plan. Hospice remains a Medicare benefit even if you have Advantage.

Most Medicare Advantage plans include drug coverage. You still need to read the formulary. “Drugs are included” is not the same as “my drugs are covered at a copay I like.”

Networks, prior authorization, and copays are the operating system:

• Networks. Some plans require in-network doctors and referrals to specialists. Other plans usually allow out-of-network care at a higher cost. If your specialist, hospital, or clinic is not in the network, Medicare Advantage can be a hard daily life — or an expensive one.

• Prior authorization. The plan may have to approve a service, a scan, a durable-medical-equipment item, or a therapy before it pays. Original Medicare plus Medicare Supplement does not work that way for most of those decisions.
• Copays and coinsurance. Instead of Medicare Supplement wiping out most leftover bills, you pay set amounts as you go — primary care, specialist, emergency room, inpatient stay. Plans must include an annual maximum out-of-pocket limit for hospital and medical services the plan covers. That cap is a real difference from Original Medicare’s uncapped 20%. You can still reach it in a heavy-care year.

Premiums can be low, including $0 plan premiums. $0 is not free. You still typically pay the Part B premium, and you pay copays when you use care. Extra benefits — limited dental, vision, hearing, fitness — are real on many plans and often the reason someone prefers Advantage. They are also often capped dollar amounts, not a full dental policy. Read the Evidence of Coverage, not the postcard.

Travel: emergency and urgent care is typically covered nationwide. Routine care is where networks bite. Snowbirds, recreational vehicle years, and kids in another state are a common reason people prefer Medicare Supplement’s “any Medicare doctor” pattern.

How to choose

List your doctors and your drugs. Then look at travel and at how you like to pay — more monthly premium for fewer surprise bills, or a lower premium with copays and plan rules.

If you need a specific specialist or clinic that is not in an Advantage network, a Supplement plus Part D is often the calmer life. If you want a lower monthly premium, are comfortable with a network, will do prior authorization when the plan asks, and value extra dental or vision benefits, Advantage may fit.

There is no universal winner. A healthy year on a $0-premium Advantage plan can look cheaper. A surgery year on Medicare Supplement can look calmer. People also change: a plan that fit at 65 can be a poor fit at 75 if specialists, drugs, or travel change. The hard part is that switching later is not always a free choice, which is the next section.

Official comparisons belong on Medicare.gov’s plan finder, not on a brokerage blog. Enter your drugs, pharmacies, and doctors there. Call 1-800-MEDICARE (1-800-633-4227) if you want the federal line.

Windows and underwriting

When you first enroll in Medicare, Medicare Supplement is typically guaranteed issue during the Medicare Supplement open enrollment period: a six-month window that starts the first month you are 65 or older and enrolled in Part B. During that window, a Medicare Supplement company generally cannot refuse you or charge you more because of health problems. That is the easy on-ramp.

Later, in many states, you may have to answer health questions to switch from Advantage to a Supplement — or to switch Medicare Supplement letters. Insurers can decline an application or rate it for health. Some states add extra consumer protections (for example, additional guaranteed-issue windows). Most do not. Do not assume you can “try Advantage for a few years and always come back” to any Medicare Supplement plan at the same price. That is why the first decision is hard to unwind. Do not guess.

Other Medicare windows are different tools:

• Initial enrollment period. About seven months around your 65th birthday month, for hospital and medical coverage (and a related window to join a Medicare Advantage or drug plan).
• Annual enrollment period. October 15 through December 7. You can switch Medicare Advantage plans, go from Advantage back to Original Medicare, join or switch Part D. Changes usually take effect January 1.
• Medicare Advantage open enrollment period. January 1 through March 31, if you already have a Medicare Advantage plan. You can switch to a different Advantage plan or drop Advantage and return to Original Medicare (and join Part D). One election in that window.
• Special enrollment periods. Moves, loss of coverage, and other qualifying events. Rules are specific; Medicare.gov is the source.

Going back to Original Medicare during annual enrollment period or Medicare Advantage open enrollment period does not automatically restore guaranteed-issue Medicare Supplement in most states. You can have Original Medicare and still be underwritten for a Supplement. There are limited federal guaranteed-issue rights (for example, certain “trial” rights if you try Medicare Advantage when you first join Medicare and leave within a set time). Those rights are narrower than the six-month Medicare Supplement open enrollment period. Read them on Medicare.gov rather than from a sales script.

Advantage vs. Supplement

Advantage vs. Supplement

	Medicare Advantage	Medicare Supplement
How it works	Private plan replaces Part A and Part B (hospice stays with Medicare)	Original Medicare pays first; Medicare Supplement pays many leftovers
Doctors	Plan network; referrals common on HMOs	Any provider that accepts Medicare
Prior authorization	Common for many services	Not the Medicare Supplement model; follows Original Medicare
Monthly cost	Often lower plan premium, more copays; you still typically pay Part B	Higher Medicare Supplement premium, more predictable bills; plus Part B and Part D
Out-of-pocket	Annual maximum out-of-pocket on plan-covered hospital and medical services	Original Medicare has no annual cap; Medicare Supplement covers much of that exposure, by letter
Drugs	Usually included (check the formulary)	Buy Part D separately (check the formulary)
Extra benefits	Often some dental, vision, hearing, fitness — read the limits	Generally not; buy those separately if you want them
Travel / other states	Emergency/urgent typically nationwide; routine care is network-based	Any Medicare-accepting provider, which is easier away from home
Switching later	annual enrollment period / Medicare Advantage open enrollment period / special enrollment periods to change plans or return to Original Medicare	After the guaranteed-issue window, underwriting is common in many states

What this page is not

This is not a plan list, an enrollment form, or a recommendation of Medicare Advantage or of any Medicare Supplement letter. Iron Tusk Insurance Group does not currently offer or enroll Medicare Advantage or Part D plans.

Do not treat a postcard, a dinner seminar, or a “your plan is changing” call as official Medicare. The federal sources are Medicare.gov and 1-800-MEDICARE. For a counselor who does not sell plans, look up your State Health Insurance Assistance Program through Medicare.gov. Rules and costs change; verify there before you enroll anywhere.

Educational only. Products, features, and availability vary by carrier and by state. This is not an offer of insurance, tax advice, or a recommendation of any specific policy. Licensed in AL, AZ, AR, CO, ID, LA, MS, MO, MT, NM, NC, SC, TN, UT, WV, WY. Iron Tusk Insurance Group, LLC. National Producer Number #22311194.