Medigap Guide

Medigap (Medicare Supplement): Plan G, Plan N & Enrollment Windows

Medigap fills the cost gaps left by Original Medicare — deductibles, coinsurance, and copays. Here's how Plan G compares to Plan N, why timing your enrollment matters, and how medical underwriting works outside your window. Reviewed with Kayla Price, licensed across 10 states.

Last reviewed: October 27, 2026

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What Is Medigap?

Medigap policies are sold by private insurers and standardized by the government into lettered plans A, B, C, D, F, G, K, L, M, and N in most states. Insurers offering the same lettered plan must cover the same standardized benefits, though premiums, pricing methods, discounts, and customer service can differ. Medigap works alongside Original Medicare, not Medicare Advantage.

Which Medigap Plan Types Are Available?

In most states, Medigap policies use standardized letter names: A, B, C, D, F, G, K, L, M, and N. An insurer may not offer every letter. Plans with the same letter provide the same basic standardized benefits, while premiums, discounts, and service can differ.

Plans C and F generally aren't available to people who became newly eligible for Medicare on or after January 1, 2020, because those plans cover the Part B deductible. Plans D and G offer comparable benefits without covering that deductible. Eligibility and state rules can vary; Massachusetts, Minnesota, and Wisconsin standardize plans differently.

Medicare SELECT is a version of a standardized Medigap policy that may require use of a provider network for full benefits; it is not a separate lettered plan.

See Medicare's official Medigap plan comparison chart and guide.

How Plan G, Plan N, and High-Deductible Plan G Differ

Plan G

Covers Medicare-approved Part A and B cost sharing after the Part B deductible ($283 in 2026). Premiums vary by insurer and can change over time.

Plan N

Plan N has different cost sharing: copays of up to $20 for some office visits and up to $50 for emergency-room visits that don't result in admission. Plan N does not cover Part B excess charges. Premiums vary by insurer and location; compare current quotes.

High-Deductible Plan G

Same standardized benefits as Plan G after you meet the annual deductible: $2,950 in 2026 and $3,050 in 2027. That deductible is your annual out-of-pocket amount for covered Medicare cost sharing before the policy pays benefits; premiums are separate. High-Deductible Plan G is available only to people new to Medicare on or after January 1, 2020. Premiums vary by insurer.

Source: CMS Medigap deductible announcements.

Is Medigap Better Than Medicare Advantage?

Medigap pairs with Original Medicare and requires a separate premium, which can vary and change over time. Standardized benefits can reduce covered out-of-pocket costs, while Medicare Advantage may have a lower premium and extra benefits in exchange for a provider network and plan-specific cost sharing.

Medigap vs. Medicare Advantage, side by side
Feature	Medigap	Medicare Advantage
Monthly premium	Separate premium; amount and future changes vary	Often $0, plus Part B premium
Deductibles	Plan-dependent (some cover Part B deductible)	Varies by plan
Provider access	Standard policies generally have no network; Medicare SELECT may require certain providers	Plan network and rules vary
Prescription coverage	Requires separate Part D plan	Often included (MA-PD)
Dental/vision/hearing	Not covered	Often included
Annual cost limit	No plan-wide out-of-pocket maximum; High-Deductible Plan G has a $3,050 deductible in 2027	Plan-specific annual limit for covered Part A/B services
Referrals needed	Generally not under Original Medicare; Medicare SELECT may require designated providers	Often, with HMO plans
What to compare	Separate premium, provider access, and Part D costs	Network, plan cost sharing, and whether Part D coverage is included

Medigap Open Enrollment Period

Your Medigap Open Enrollment Period is a one-time, 6-month window that starts the month you're 65 or older and enrolled in Medicare Part B. During this window, you can buy any Medigap policy an insurer offers in your state without medical underwriting based on pre-existing health conditions.

Outside that window — or outside a guaranteed-issue right, such as losing other coverage involuntarily — insurers can use medical underwriting: asking health questions and potentially charging more or denying coverage based on your answers. This is the single most important timing decision in Medigap shopping.

Not sure if you're inside your window? Schedule a consultation with a Medicare agent to confirm your timing before you apply.

Frequently Asked Questions

What is Medigap?

Medigap, or Medicare Supplement insurance, is a private insurance policy that works alongside Original Medicare to help cover out-of-pocket costs like deductibles, copays, and coinsurance.

What Medigap plan letters are available?

Most states use standardized Medigap plans A, B, C, D, F, G, K, L, M, and N. Plans C and F generally aren't available to people newly eligible for Medicare on or after January 1, 2020. Massachusetts, Minnesota, and Wisconsin standardize plans differently.

What is the difference between Plan G and Plan N?

Plan G covers Medicare-approved cost sharing after the Part B deductible, subject to its standardized benefits. Plan N has different cost sharing, including copays for some office and emergency-room visits, and does not cover Part B excess charges. Premiums for either plan vary by insurer and location.

What is High-Deductible Plan G?

High-Deductible Plan G offers the same standardized benefits as Plan G after you meet its annual deductible. The deductible is $2,950 in 2026 and $3,050 in 2027; premiums vary by insurer. High-Deductible Plan G is available only to people who are new to Medicare on or after January 1, 2020.

When is the best time to enroll in Medigap?

Your Medigap Open Enrollment Period is the 6-month window starting the month you're 65 or older and enrolled in Part B. During this period, you can buy any Medigap policy an insurer offers in your state without medical underwriting based on pre-existing health conditions.

Can I be denied a Medigap policy?

Outside your Medigap Open Enrollment Period or a qualifying guaranteed-issue situation, insurers can use medical underwriting and may deny coverage or charge higher premiums based on your health history.

Does Medigap cover prescription drugs?

No. Medigap plans don't include prescription drug coverage — you'll need a separate Part D plan alongside your Medigap policy.

Can I switch Medigap plans later?

Yes, but outside your initial enrollment window or a guaranteed-issue right, switching typically requires medical underwriting, and the new insurer can decline you or adjust pricing based on health.

Is Medigap the same in every state?

Most states use standardized Medigap plans A, B, C, D, F, G, K, L, M, and N with identical benefits for each letter between insurers, though pricing varies. A few states use different rules — always confirm what's available where you live.

Reviewed by Kayla Price

Licensed Insurance Agent | NPN: 18530055

Licensed in NC, SC, GA, FL, VA, MD, MI, KS, TX, OH