Neither Medicare Advantage nor Medigap is universally better. The right choice depends on your budget, how much you value provider flexibility, and how comfortable you are with unexpected medical costs. Medigap offers more predictable expenses and wider provider access but costs more each month. Medicare Advantage keeps monthly premiums low (often $0) and bundles extras like dental and vision, but limits your provider choices and can leave you with significant bills if you get seriously ill.
How Each Plan Actually Works
Medigap and Medicare Advantage are fundamentally different products, even though both supplement your Medicare coverage. Medigap (also called Medicare Supplement Insurance) works alongside Original Medicare. You keep Parts A and B, see any doctor who accepts Medicare, and your Medigap policy picks up some or all of the copays, coinsurance, and deductibles that Original Medicare leaves behind. You pay a monthly premium to a private insurer for this gap coverage.
Medicare Advantage replaces Original Medicare entirely. A private insurer runs your plan, and you get all your Part A and Part B benefits through them, usually with prescription drug coverage bundled in. In exchange for lower premiums, you agree to use the plan’s provider network and follow its rules about referrals and pre-approvals.
One critical distinction: Medigap does not include prescription drug coverage. You need to buy a separate Part D plan for medications, which adds another monthly premium. Most Medicare Advantage plans include drug coverage by default.
Monthly Costs vs. Total Costs
The premium gap between the two options is substantial. Many Medicare Advantage plans charge $0 per month beyond your standard Part B premium. Medigap is significantly more expensive up front. The average monthly premium across all Medigap policyholders was $217 in 2023. Plan G, the most popular option for new enrollees, averaged $164 per month, ranging from about $140 in lower-cost states to $236 in New York. Plan N, a slightly less comprehensive option, averaged $168.
But monthly premiums only tell half the story. Where Medigap earns back its higher cost is in what happens when you actually use healthcare. With a comprehensive Medigap plan like Plan G, your only remaining cost-sharing for the year is the Part B deductible ($283 in 2026). After that, covered services are essentially free to you. With Plan N, you pay small copays for some office and emergency room visits, but your exposure is still minimal.
Medicare Advantage plans have an out-of-pocket maximum that caps your yearly spending, but that cap can be high. The federal ceiling for 2025 is $9,350 for in-network services and $14,000 when out-of-network care is included. The average cap across plans is about $5,320 in-network. That means a serious illness or hospitalization could cost you thousands in a single year on a Medicare Advantage plan, while a Medigap policyholder with Plan G would pay almost nothing beyond their monthly premium.
For healthy people who rarely see doctors, Medicare Advantage’s low premiums can save real money. For people with chronic conditions or those who want to budget precisely, Medigap’s higher premium buys near-total cost predictability.
Provider Access and Referrals
This is where the two options diverge most sharply. With Medigap and Original Medicare, you can see any doctor or specialist in the country who accepts Medicare, with no referrals needed. If you want a second opinion at a major medical center in another state, you just go.
Medicare Advantage plans use networks. HMO plans require you to choose a primary care physician, get referrals for specialists, and stay in-network for all non-emergency care. If you see an out-of-network provider, you typically pay 100% of the cost yourself. PPO plans offer more flexibility, letting you see out-of-network doctors without a referral, but at a higher cost-sharing rate.
Medicare Advantage plans also rely heavily on prior authorization, a process where the plan must approve certain services before you receive them. About 80% of Medicare Advantage enrollees are in plans that require prior authorization for at least one Medicare-covered service. At least 70% are in plans requiring it for things like durable medical equipment, certain drugs, skilled nursing stays, and hospital admissions. More than half are in plans requiring it for mental health services. Original Medicare, by contrast, requires prior authorization only in very limited circumstances.
Dental, Vision, and Hearing Benefits
Medicare Advantage’s biggest selling point beyond price is its supplemental benefits. Most plans include some level of dental, vision, and hearing coverage that Original Medicare does not provide. These extras are a genuine advantage, since Medigap policies don’t cover dental, vision, or hearing at all.
That said, these benefits are often more limited than they appear. Among Medicare Advantage enrollees with access to more extensive dental coverage, 78% are in plans with annual dollar limits that average $1,300. More than half are in plans capping dental benefits at $1,000 or less per year. That covers cleanings and basic work but can fall short for crowns, implants, or dentures. If you’re on Original Medicare with Medigap, you’d need to buy standalone dental, vision, and hearing coverage separately, but you can choose plans with higher limits if you need them.
Travel and Coverage Away From Home
If you travel frequently, Medigap has a clear edge. Most Medigap plans (including the popular G and N plans) cover 80% of emergency medical costs outside the United States after a $250 yearly deductible, up to a $50,000 lifetime limit. Coverage applies during the first 60 days of a trip.
Medicare Advantage coverage outside the U.S. varies by plan and is often minimal. Some plans offer limited foreign emergency coverage, but many do not. Even within the U.S., an HMO-style Advantage plan may not cover non-emergency care outside your plan’s service area, which matters if you spend winters in another state.
Switching Plans Later
This is the factor most people underestimate when making their initial choice. Medicare Advantage plans can be changed every year during open enrollment. If you don’t like your plan, you pick a different one. That flexibility is straightforward.
Medigap enrollment works very differently. You get one six-month open enrollment window, starting the first month you have Part B and are 65 or older. During that window, insurers must sell you any Medigap policy they offer at standard rates, regardless of your health. This window does not repeat. After it closes, insurers can use medical underwriting to evaluate your application. They can charge you more based on health conditions, limit your plan choices, or deny you coverage entirely.
This creates an important strategic consideration. If you start with Medicare Advantage at 65 and later decide you want to switch to Medigap in your 70s (perhaps because your health has changed and provider flexibility matters more), you may not be able to get a Medigap policy at an affordable price, or at all. If you start with Medigap during your open enrollment window, you lock in guaranteed coverage. You can always switch to Medicare Advantage later during annual enrollment if you want to lower your premiums.
Who Benefits Most From Each Option
Medicare Advantage tends to work well for people who are relatively healthy, comfortable using a provider network, live in one place year-round, and want the lowest possible monthly cost. The bundled dental, vision, and drug coverage simplifies things, and if you don’t use much healthcare, your total annual spending stays low.
Medigap tends to work well for people who have ongoing health needs, want to see specialists without restrictions, travel often, or simply want financial predictability. You’ll pay more each month, but you’ll almost never face a surprise medical bill. It also suits people who live in rural areas where Medicare Advantage networks may be thin.
One factor worth weighing: your comfort with risk. Medicare Advantage is essentially a bet that your healthcare costs in a given year will stay low enough that the savings on premiums outweigh the higher cost-sharing. Medigap is paying a known premium to eliminate most of that financial uncertainty. The older you get and the more healthcare you use, the more that trade-off tilts toward Medigap, which is exactly why the enrollment rules make it harder to switch in that direction later.