Medicare Advantage vs Medigap in 2026: How to Choose the Right Supplement

When you become eligible for Medicare, the decision you make about supplemental coverage can affect your healthcare costs and access for years or decades. Medicare alone leaves significant gaps in coverage, including Part A deductibles, Part B coinsurance at 20% of all outpatient costs with no annual cap, and no coverage for dental, vision, or hearing. Two fundamentally different approaches exist for filling these gaps: Medicare Advantage replaces original Medicare entirely with a private managed care plan, while Medigap supplements original Medicare by covering some or all of the gaps. The right choice depends on your health, finances, and how you want to access care.

How Medicare Advantage Works

Medicare Advantage (Part C) plans are offered by private insurance companies that contract with Medicare to provide all of your Part A and Part B benefits. Instead of Medicare paying your bills directly, you use your Advantage plan for all care. Most Advantage plans also include Part D drug coverage and often add extras like dental, vision, hearing, and fitness benefits that original Medicare does not cover. In exchange, most Advantage plans use a managed care structure, typically HMO or PPO, that limits which doctors and hospitals you can use at the in-network rate.

Medicare Advantage plans often have lower or even $0 monthly premiums compared to Medigap plans, which attracts many enrollees. However, the low premium is offset by cost-sharing at the point of care: copays for office visits, specialist visits, and procedures, plus coinsurance for hospitalizations. All Advantage plans must have an annual out-of-pocket maximum, capped at $9,350 for in-network care in 2026, which limits your worst-case exposure in a major health year. If you exceed the maximum, the plan covers 100% of remaining covered costs for the year.

How Medigap Works

Medigap policies, also called Medicare Supplement Insurance, work alongside original Medicare (Parts A and B). When you receive care, Medicare pays its share and the Medigap policy pays some or all of the remaining cost, depending on the plan type you choose. You continue using original Medicare as your primary insurance, which means you can see any doctor or use any hospital in the country that accepts Medicare. There are no networks, no referrals required, and no prior authorization requirements beyond whatever Medicare itself requires.

Medigap plans are standardized by the federal government and identified by letters (Plan G, Plan N, Plan K, etc.), meaning a Plan G from one company provides identical coverage to a Plan G from another company. The only difference between companies is the premium they charge. Plan G is currently the most comprehensive Medigap plan available to new Medicare enrollees (Plan F, which covered the Part B deductible, was discontinued for new enrollees in 2020). Medigap premiums are typically $100-$300 per month depending on your age, location, and the insurance company, in addition to the standard Part B premium.

The Network Trade-Off: Freedom vs. Cost

The most significant practical difference between Advantage and Medigap is network access. With Medigap, you can see any Medicare-accepting provider anywhere in the country with no referrals and no network restrictions. This matters enormously if you travel, have a second home, or want to see specialists at major academic medical centers. Medicare-accepting providers do not need to be in any particular plan's network because there is no network in the traditional Medicare system.

Medicare Advantage HMO plans typically require you to use in-network providers for all non-emergency care, and seeing a specialist usually requires a referral from your primary care physician. PPO plans allow out-of-network care but at higher cost-sharing rates. If you travel frequently or live in a rural area with limited network options, the Advantage structure can be a significant constraint. If you mainly see local doctors who are in your plan's network and rarely travel, the network restriction may never matter to you in practice.

Cost Comparison in High-Cost Health Years

The financial comparison between Advantage and Medigap looks different in healthy years versus years with significant health needs. In a healthy year with few doctor visits, Advantage's low or zero premium wins the comparison easily. In a year with major health events, the out-of-pocket maximum on an Advantage plan limits your exposure, but you pay significant cost-sharing along the way. With a comprehensive Medigap plan like Plan G, your cost-sharing is nearly zero after your deductibles, but you pay the higher monthly premium regardless of how much care you use.

A simple break-even analysis: if a Medigap Plan G costs $2,400 per year in premiums more than an Advantage plan, you need at least $2,400 in cost-sharing under the Advantage plan to break even. People with chronic conditions that require frequent specialist visits, regular diagnostic testing, and ongoing medications may easily exceed this threshold, making Medigap the better value. People who are generally healthy and rarely exceed $2,400 in annual out-of-pocket costs may be better served financially by Advantage.

The Switching Problem: Why Your Initial Choice Matters

When you first become eligible for Medicare at 65, you have guaranteed issue rights for Medigap during your six-month Initial Enrollment Period, meaning insurers cannot deny you coverage or charge you more due to pre-existing conditions. After this window closes, most states allow Medigap insurers to use medical underwriting, meaning they can decline to issue you a policy or charge much higher premiums if you have health conditions. This creates a problem for people who start with Advantage and later want to switch to Medigap: they may be unable to get Medigap coverage at standard rates.

A few states, including New York, California, and Massachusetts, require Medigap insurers to accept all applicants regardless of health status, allowing switching in either direction at any time. In most states, once you are in Advantage and your health declines, switching to Medigap may become very expensive or impossible without a qualifying life event that triggers special enrollment rights. This asymmetry is one reason financial advisors often recommend that people who can afford the premiums start with Medigap while they are healthy. Use our Medicare benefits calculator to estimate your coverage costs, and read our guide on Medicare versus Medicaid for additional background on the programs.