How to Choose the Best Medicare Supplement Plan

# How to Choose the Best Medicare Supplement Plan

Medicare Supplement insurance—also called Medigap—fills the cost-sharing gaps that Original Medicare leaves behind: deductibles, coinsurance, and copayments that can otherwise accumulate without any annual ceiling. Choosing among plan letters, carriers, and pricing structures can feel overwhelming, but Medigap is highly standardized—once you understand the framework, comparing your options becomes manageable.

What Medigap Is—and What It Is Not

A Medicare Supplement plan is private insurance that works alongside Original Medicare (Parts A and B)—not instead of it. You must be enrolled in both Part A and Part B to buy a Medigap policy.

Key structural facts:

• Benefits are federally standardized by letter. Every Plan G from every carrier covers the same benefits. What varies is the monthly premium and the carrier's financial strength and service reputation.
• Medigap does not include drug coverage. You will need a separate Part D standalone prescription drug plan.
• Medigap does not work with Medicare Advantage. You cannot have both simultaneously. Medigap supplements Original Medicare; Medicare Advantage replaces it.
• Provider access is broad. You can see any provider who accepts Medicare—nationwide, with no referrals and no network restrictions.

That last point matters most for people who travel frequently, split time between states, or have specialists they want to keep regardless of a carrier's network.

Understanding the Most Common Plan Letters

CMS has standardized Medigap into lettered plans (A, B, D, G, K, L, M, N—and F for those eligible before January 1, 2020). Most new enrollees today compare Plan G and Plan N, with Plan F still relevant for those grandfathered into eligibility.

Plan G is the most popular plan for new Medicare enrollees. It covers the Part A inpatient hospital deductible, Part A and B coinsurance and copayments, skilled nursing facility coinsurance, Part B excess charges (when a provider charges above Medicare's approved amount), and foreign travel emergency care. The one cost Plan G does not cover is the annual Part B deductible, which you pay once per year. After that, your out-of-pocket exposure for covered services is essentially zero.

Plan N offers similar core coverage but requires small copayments for office and emergency room visits that don't result in a hospital admission, and does not cover Part B excess charges. Its lower monthly premium can make it a reasonable choice if you see doctors infrequently and your providers accept Medicare assignment.

Plan F covers everything Plan G does plus the Part B deductible. It is only available to beneficiaries who were eligible for Medicare before January 1, 2020.

How Medigap Premiums Are Priced

Federal law standardizes what each plan covers, but premiums are set by carriers and can vary significantly for the same plan letter. There are three pricing methods:

• Community-rated: Everyone in the same plan pays the same premium regardless of age. Premiums can still rise with inflation, but not simply because you get older.
• Issue-age-rated: Your premium is locked to your age at purchase and doesn't increase as you age (though it may rise with inflation).
• Attained-age-rated: Your premium rises each year as you age. These plans often start lowest but can become the most expensive over time.

Which pricing method a carrier uses matters more than the current monthly premium. A low attained-age premium may look attractive at 65 but become burdensome by 75 or 80.

When to Buy—and What to Know About Underwriting

Your Medigap Open Enrollment Period begins the month you are both age 65 and enrolled in Part B, and lasts six months. During this window, carriers cannot deny you coverage, charge you more for pre-existing conditions, or make you wait for coverage to begin.

Outside this window—if you try to switch plans later or missed your open enrollment—most carriers can apply medical underwriting, meaning they can decline your application or charge higher premiums based on your health history. A few states have additional protections, but federal law only guarantees that initial 6-month window. The practical implication: enroll in the Medigap plan you want during open enrollment, even if your health is excellent right now.

Frequently Asked Questions

Q: Is Plan G always the best Medicare Supplement plan? A: Plan G is the most comprehensive option for new enrollees and covers nearly all out-of-pocket costs under Original Medicare. But "best" depends on your health, budget, and how much you value premium savings versus coverage certainty. Plan N can be a cost-effective alternative if you see doctors infrequently and your providers accept Medicare assignment.

Q: Can I switch Medigap plans after my open enrollment period? A: In most states, switching after your initial 6-month open enrollment requires passing medical underwriting, and carriers can decline you or charge more based on your health. Some states offer additional guaranteed-issue rights—birthday rules in California, Oregon, and a growing number of states allow annual switches without underwriting. Check your state's rules or speak with an advisor.

Q: Does Medigap cover prescription drugs? A: No. Medigap plans do not include prescription drug coverage. If you choose Original Medicare with a Medigap supplement, you will need to enroll in a separate Part D standalone drug plan to have prescription coverage. Failing to enroll in Part D when you are first eligible can result in a late enrollment penalty if you go without creditable drug coverage for more than 63 consecutive days.

Have questions about your Medicare options? Lynsey Brennan (FL License #G007269) offers free consultations in FL, TX, AZ, GA, NC, SC, PA, OH, TN, VA. Call (561) 735-1490 or book online.

We do not offer every plan available in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options.