How to Compare Medicare Supplement Plans and Pick the Right One

Original Medicare covers a lot, yet it doesn't cover everything. There is no out-of-pocket maximum on Part A and Part B, which means a long hospital stay or frequent outpatient care can leave you with thousands of dollars in coinsurance bills. That's why millions of beneficiaries buy a Medicare Supplement policy, often called Medigap, to plug the gaps. The challenge is that ten standardized Medigap plans exist, and they are not all created equal. Comparing them side by side is the only way to avoid paying for coverage you don't need or skipping coverage you'll wish you had.

First, Understand What Medicare Supplement Actually Does

A Medigap plan is private insurance that pays some of the costs Original Medicare passes on to you, such as the Part A hospital deductible, the Part B 20 percent coinsurance, and skilled nursing facility coinsurance. Every Medigap policy is standardized in most states, meaning a Plan G from one insurer must offer the exact same benefits as a Plan G from another insurer. The only real differences are price, customer service, and rate-increase history.

You must already have Medicare Part A and Part B to buy a Medigap plan. You pay a separate monthly premium to the insurance company on top of your Part B premium. You can use any doctor or hospital in the country that accepts Medicare, which is one of the biggest advantages over Medicare Advantage plans.

The Main Plans Worth Comparing

Although ten plans exist (A, B, C, D, F, G, K, L, M, and N), most shoppers end up comparing just three or four. Here's how the heavy hitters stack up.

  • Plan G – The current go-to choice for new enrollees. It covers everything Original Medicare doesn't except the Part B deductible (which is $240 in 2024). That means once you pay the Part B deductible, your Medicare-approved bills are covered at 100 percent. Premiums are higher than Plan N but lower than Plan F.
  • Plan N – A budget-friendly option with lower premiums. It covers the Part A deductible and coinsurance in full, but it charges up to $20 for some office visits and up to $50 for emergency room visits that don't result in admission. You also pay excess charges if a doctor bills above Medicare's approved amount (rare, but possible).
  • Plan F – The most comprehensive plan ever sold. It covers every gap, including the Part B deductible. However, it's closed to people who became eligible for Medicare after January 1, 2020, so it's only available if you had Medicare before that date.
  • High-Deductible Plan G – A newer option that offers the same coverage as regular Plan G but with a much lower premium and a $2,800 annual deductible (2024). You pay all costs up to that amount out of pocket, which works well for healthy beneficiaries who want catastrophic protection.

How to Compare the Alternatives You Actually Have

You have two real paths once you decide Original Medicare isn't enough on its own. Comparing Medicare Supplement to Medicare Advantage is the first decision most people face.

Medicare Supplement (Medigap): Higher monthly premium, very low out-of-pocket costs, no network restrictions, no referrals, and coverage that travels with you nationwide. You also need a separate Part D drug plan.

Medicare Advantage (Part C): Lower or zero monthly premium, but copays, coinsurance, and an annual out-of-pocket maximum (around $8,850 for in-network care in 2024). You must use the plan's network, get referrals in some cases, and live in the service area. Most plans bundle Part D drug coverage.

If you travel frequently, see multiple specialists, or simply want predictable costs, Medigap usually wins. If you prefer lower premiums, are comfortable with a network, and want extras like dental or vision, Medicare Advantage can be a smart trade.

Five Factors to Weigh Before You Choose a Plan

  • Your health and budget – If you can afford a higher monthly premium, Plan G offers peace of mind. If you'd rather save monthly and accept some cost-sharing, Plan N or a Medicare Advantage plan may fit.
  • Doctor access – Medigap lets you see any Medicare provider. Medicare Advantage restricts you to networks. If your specialists are must-keeps, check the network first.
  • Rate stability – Medigap premiums rise with age and medical claims. Ask each company for its three-year rate-increase history. A plan that's cheap now but jumps 15 percent a year will cost you more in the long run.
  • Household discounts and perks – Many insurers offer 5 to 12 percent discounts for spouses, non-smokers, or paying annually. A few also include gym memberships or telehealth. These don't change coverage but can sweeten the deal.
  • Enrollment timing – Your Medigap Open Enrollment Period is the six months after you turn 65 and enroll in Part B. During this window, insurers cannot reject you or charge more because of pre-existing conditions. After that window, they can. Don't miss it if you want the broadest choice.

Putting It All Together

Start by deciding between Original Medicare plus a Medigap plan and a Medicare Advantage plan. That choice drives everything else. If you pick the Medigap route, get quotes for the same plan letter from at least three to five reputable insurers in your state, since prices for identical coverage can vary by 50 percent or more. Look beyond the first-year premium and check the company's history of rate hikes, financial strength ratings, and customer reviews.

Most people who want comprehensive, no-surprise coverage land on Plan G. Budget-conscious shoppers who can handle small copays often choose Plan N. People who want catastrophic coverage with the lowest monthly cost gravitate to high-deductible Plan G. And anyone still eligible for Plan F who values paying nothing out of pocket at the doctor may keep that plan as long as the premium is reasonable.

The right plan is the one that balances your monthly budget, your health needs, and your tolerance for out-of-pocket surprises. Compare benefits first, then compare prices for the same standardized plan, and you'll end up with coverage that fits your retirement instead of fighting it.