More than half of all Medicare beneficiaries now face the same decision: should they choose Medicare Advantage or Medicare Supplement coverage? The difference between Medicare Advantage and Medicare Supplement comes down to how you receive your benefits, how much you pay, and how much flexibility you have in choosing providers. Getting this decision right can save you thousands of dollars and prevent frustrating coverage surprises. This guide explains each option in plain language, weighs the genuine trade-offs on both sides, and helps you evaluate which one fits your healthcare needs. Neither path is “better” for everyone – the right answer depends on your health, budget, travel habits, and how much predictability you want.
Medicare Advantage vs. Medigap at a Glance
Before the details, here is a quick side-by-side of the two approaches. Every dollar figure below moves each year and varies by plan and location, so treat these as ranges to verify at Medicare.gov, not fixed quotes.
| Feature | Medicare Advantage (Part C) | Medicare Supplement (Medigap) |
|---|---|---|
| How it works | Replaces Original Medicare; private plan delivers Part A & B | Works alongside Original Medicare; pays the gaps |
| Monthly premium | Often low or $0 (plus your Part B premium) | Typically higher (roughly $90-$300+, plus Part B premium) |
| Provider access | Network-based (HMO/PPO); referrals often required | Any provider in the U.S. that accepts Medicare |
| Prior authorization | Common for imaging, procedures, equipment | Rare for Medicare-covered services |
| Out-of-pocket cap | Yes – annual in-network cap set by CMS | No formal cap needed; Plan G leaves only the Part B deductible |
| Drug coverage | Usually bundled in (MAPD plans) | Buy a separate standalone Part D plan |
| Extra benefits (dental/vision/hearing) | Frequently included | Not included; buy separately |
The Fundamental Structural Difference
The core difference between Medicare Advantage and Medicare Supplement is structural. Medicare Advantage (Part C) replaces Original Medicare. When you enroll in an Advantage plan, your Part A and Part B benefits are delivered through a private insurance company instead of the federal government. The plan determines your copays, coinsurance, provider network, and prior authorization requirements. You still pay your Part B premium, and most plans add little or no premium on top.
Medicare Supplement (Medigap) works alongside Original Medicare. You keep Parts A and B, see any provider that accepts Medicare, and your Medigap policy pays the cost-sharing gaps that Original Medicare leaves behind. There are no networks, no referrals, and no prior authorization for covered services. Your Medigap insurer simply picks up the tab for deductibles, coinsurance, and other out-of-pocket costs. Medigap policies are standardized by letter (A, B, C, D, F, G, K, L, M, N), so a Plan G from one insurer covers the same benefits as a Plan G from another – only the price and service differ.
Cost Structure Differences
Medicare Advantage plans often attract enrollees with $0 monthly premiums. However, you face cost-sharing every time you use services. Primary care copays of roughly $0 to $20, specialist copays of about $25 to $50, hospital copays of a few hundred dollars per day, and an annual maximum out-of-pocket limit are typical. CMS sets the maximum in-network out-of-pocket limit each year; in recent years it has run to roughly $9,000 or more for in-network care (verify the current figure, and note out-of-network care under a PPO can push a separate, higher combined limit). If you have a serious health event, costs can accumulate quickly before you reach that annual maximum – but once you hit it, the plan covers 100% of in-network Medicare-covered services for the rest of the year.
Medigap premiums are higher, typically in the range of $90 to $300 or more per month depending on the plan letter, your age, location, and the insurer’s rating method. But your out-of-pocket costs at the point of care are minimal. With Plan G, the most popular Medigap option for new enrollees, you pay only the annual Part B deductible (a figure that has run in the mid-$200s in recent years and adjusts annually – confirm the current amount). After that, you pay nothing for Medicare-covered services for the rest of the year. Add a standalone Part D drug plan premium of roughly $0 to $60 per month, and your total predictable monthly cost with Medigap is higher, but your cost variability is close to zero.
According to KFF research, the average Medicare Advantage enrollee tends to spend less out of pocket in healthy years but can spend significantly more during years with major health events compared to Medigap enrollees. In short, Advantage often wins on cash flow when you are well; Medigap often wins on protection when you are sick. For detailed cost comparisons, see our Medigap Cost Comparison Chart and our Medicare Supplement Plans Cost guide.
Provider Access and Network Restrictions
With Medigap and Original Medicare, you can see any doctor, specialist, or hospital in the United States that accepts Medicare. The large majority of non-pediatric physicians participate in Medicare, and there are no referrals needed and no network to verify. If you are traveling and need care, your coverage works identically in all 50 states, and most Medigap plans add limited foreign-travel emergency coverage.
Medicare Advantage plans use defined provider networks. HMO plans generally restrict you to in-network providers except in emergencies and typically require referrals to specialists. PPO plans allow out-of-network visits at higher cost-sharing. If your doctor leaves the network or you move to a new area, you may need to find new providers or switch plans, and networks can change from year to year. For beneficiaries who travel frequently, split time between states, or have established relationships with specific specialists or a particular cancer center, this difference is often the deciding factor. Always confirm your key doctors and hospitals are in-network before enrolling, and re-check each year.
Prescription Drug Coverage
Most Medicare Advantage plans include Part D prescription drug coverage as part of the plan (these are called MAPD plans). You pay one premium for medical and drug benefits, and the plan manages your drug formulary, copays, and coverage phases. This bundling is convenient, but it means you generally cannot choose your drug plan independently of your medical plan – and enrolling in a standalone Part D plan can disenroll you from many Advantage plans.
With Medigap, you need a separate standalone Part D plan for drug coverage. This lets you choose the Part D plan with the best formulary for your specific medications, independent of your medical coverage. However, it means managing two separate insurance products and two enrollment decisions. Both paths now benefit from the redesigned Part D benefit, which includes an annual out-of-pocket cap on covered drugs (in the low-$2,000s and indexed to rise over time – verify the current figure). Learn about drug coverage details in our Part D donut hole article.
Extra Benefits Comparison
Medicare Advantage plans frequently include benefits that Medigap cannot offer. Common extras include routine dental coverage (cleanings, fillings, and sometimes crowns or dentures), routine vision (exams and eyewear), hearing aids and hearing exams, fitness memberships like SilverSneakers, over-the-counter item allowances, transportation to medical appointments, meal delivery after hospitalizations, and telehealth. For many enrollees, these extras are the single biggest draw of Advantage.
Medigap plans cover only the cost-sharing gaps in Original Medicare. They do not include dental, vision, hearing, fitness, or prescription drug benefits. To get these services with Medigap, you need separate policies or discount plans. The extra benefits in Medicare Advantage are genuine added value, though the scope, dollar limits, and quality vary significantly between plans, and some benefits come with their own networks or annual caps. Always read the plan’s Evidence of Coverage and Summary of Benefits to understand what is actually included and what it pays.
Prior Authorization and Care Management
One often-overlooked difference between the two approaches involves prior authorization. Many Medicare Advantage plans require prior authorization before they will approve certain services, including advanced imaging (MRI, CT scans), specialist procedures, durable medical equipment, skilled nursing facility stays, and some prescription drugs. If the plan denies prior authorization, you may need to appeal or pay out of pocket. Appeals often succeed, but they take time and effort at a stressful moment.
With Original Medicare and Medigap, prior authorization is rarely required for Medicare-covered services. Your doctor orders the service, Medicare pays its share, and your Medigap policy pays the rest. This difference can be significant for beneficiaries who need timely access to specialists, procedures, or equipment. CMS has been implementing regulations to streamline and reduce prior authorization burdens in Medicare Advantage, including faster decision timelines and electronic processing, but the practice remains widespread. It is a genuine trade-off, not a reason by itself to rule out Advantage – many enrollees never hit a denial.
Medical Underwriting and the Closed Plans
Timing and health status shape which Medigap plans you can buy and at what price. During your Medigap Open Enrollment Period – the six months beginning when you are 65 or older and enrolled in Part B – insurers must sell you any Medigap policy they offer at the best available rate, regardless of health. Miss that window, and in most states insurers can use medical underwriting: they can review your health, charge more, or decline you outside of specific guaranteed-issue situations.
Two popular plans are also now closed to newer beneficiaries. Because of a 2015 law, Medigap Plans C and F – which covered the Part B deductible – are not available to people who became eligible for Medicare on or after January 1, 2020. If you were eligible before that date, you may still be able to buy or keep them. For most new enrollees today, Plan G offers nearly identical protection minus the Part B deductible, which is why it has become the most popular choice. See our guide on the best Medicare Supplement plan for how the letters compare.
Switching Between the Two Options
Switching from Medigap to Medicare Advantage is easy. You can join an Advantage plan during any eligible enrollment period (the Annual Election Period, your Initial Enrollment Period, or a qualifying Special Enrollment Period) and drop your Medigap policy. The transition is generally seamless.
Going the other direction is much harder. If you have been on Medicare Advantage for more than 12 months and want to switch back to Original Medicare with Medigap, insurers in most states can require medical underwriting. If you have developed health conditions while on Advantage, you may be denied Medigap coverage or charged significantly higher premiums. There is a “trial right” that protects some people who try Advantage for the first time and switch back within 12 months, but it is limited. This asymmetry is one of the most important factors in understanding the difference between Medicare Advantage and Medicare Supplement.
A few states offer protections that ease this transition. Maryland provides guaranteed-issue rights for certain Medigap plans when leaving Advantage. California’s birthday rule allows annual Medigap switching for current Medigap holders, and several other states have their own continuous or annual guaranteed-issue rules. But in most states, choosing Advantage is effectively a one-way decision for beneficiaries who develop health conditions. Rules change, so verify your state’s current protections. See our state-specific guides for California, Maryland, and Pennsylvania.
Get Free, Unbiased Help
You do not have to sort this out alone, and you should be cautious about relying only on a commissioned agent who sells one type of plan. Every state has a State Health Insurance Assistance Program (SHIP) that offers free, unbiased one-on-one Medicare counseling. A SHIP counselor can help you compare specific plans in your ZIP code, check whether your drugs and doctors are covered, and understand your enrollment windows. You can also use the Plan Finder and coverage tools at Medicare.gov to compare real plans and prices for your situation. Because plans, premiums, and rules change every year, verifying the current details for your county is the single most valuable step you can take.
Frequently Asked Questions
Can I have both Medicare Advantage and Medigap?
No. Federal law prohibits holding both at the same time. An insurer cannot legally sell you a Medigap policy while you are enrolled in a Medicare Advantage plan. You must choose one path, and a Medigap policy does not work with (or pay the cost-sharing of) an Advantage plan.
Which option is better for someone with chronic conditions?
Many people with chronic conditions favor Medigap because it provides unrestricted access to specialists, little to no prior authorization for Medicare-covered services, and predictable low out-of-pocket costs. That said, some Advantage plans, including Special Needs Plans (SNPs) built around specific conditions, offer coordinated care and extra benefits that suit certain enrollees well. The best choice depends on your specific providers, medications, and how much cost predictability you want. Compare specific plans rather than assuming.
Is Medicare Advantage going away?
No. Medicare Advantage enrollment has been growing steadily and now covers more than half of all Medicare beneficiaries. However, CMS regularly adjusts payment rates and regulations, which can affect plan availability and benefits from year to year. Plans are reviewed and renewed annually, and specific plans can leave a county or change their benefits, so review your coverage each fall.
What about Medicare Supplement plans for 2026?
Medigap plan benefits are standardized and are not changing in structure for 2026 – the plan letters and what each covers remain the same. Premiums adjust annually based on insurer rate filings, and Plans C and F remain closed to those first eligible on or after January 1, 2020. For current cost estimates, visit our Medicare Supplement Plans Cost guide, and always confirm live quotes at Medicare.gov.
Which option is better if I travel?
Medigap is generally better for travelers. Original Medicare covers you at any Medicare-participating provider in the country, and most Medigap plans include limited foreign-travel emergency coverage. Medicare Advantage networks are geographically limited, which can leave you with out-of-network costs or coverage gaps when traveling, though PPO plans and emergency coverage soften this. If you split the year between states, check each plan’s rules carefully.
Do the 2026 dollar amounts in this article change?
Yes. Premiums, the Part B deductible, the Advantage out-of-pocket maximum, and the Part D cap all adjust from year to year and vary by plan and location. Use the figures here as general ranges and confirm the current numbers at Medicare.gov or with a SHIP counselor before you enroll.
Making Your Decision
The right choice depends on your personal priorities. If you value low monthly premiums, bundled benefits, and are comfortable with provider networks and occasional prior authorization, Medicare Advantage may work well for you. If you prioritize provider freedom, predictable costs, and comprehensive coverage without prior authorization, Medigap is likely the better fit. Consider your health status, expected healthcare usage, travel plans, and budget. For many beneficiaries, the difficulty of switching from Advantage to Medigap later is the most compelling reason to consider starting with Medigap – you can generally move to Advantage anytime, but the reverse path is not guaranteed. Others reasonably prefer Advantage for the lower premiums and extra benefits and accept the network and authorization trade-offs. There is no universally correct answer, only the one that fits your situation. For additional planning resources, visit our healthcare policy guide and our guide on what is the best Medicare Supplement plan.
TL;DR & disclaimer: Medicare Advantage replaces Original Medicare with a private plan that has a network, cost-sharing, and often prior authorization, usually at a low premium plus extra benefits and an annual out-of-pocket cap. Medicare Supplement (Medigap) works alongside Original Medicare, costs more in premium but leaves very low out-of-pocket costs and lets you see any Medicare provider, though you add a separate Part D drug plan. Switching from Advantage back to Medigap can require medical underwriting in most states and is not guaranteed, and Plans C and F are closed to those newly eligible on or after January 1, 2020. All dollar figures change yearly and vary by plan and location – this article is general information, not insurance or financial advice. Confirm current details at Medicare.gov and get free help from your State Health Insurance Assistance Program (SHIP) before enrolling.
Sources
- Medicare.gov – “Medicare Advantage Plans” and “Medigap (Medicare Supplement Insurance)” (medicare.gov)
- Centers for Medicare & Medicaid Services (CMS) – Medicare Advantage out-of-pocket maximums, prior authorization regulations, and Part D benefit redesign (cms.gov)
- KFF (Kaiser Family Foundation) – research on Medicare Advantage vs. traditional Medicare out-of-pocket spending and enrollment trends (kff.org)
- State Health Insurance Assistance Programs (SHIP) – free local Medicare counseling (shiphelp.org)