Medicare Supplement Plans Comparison Chart: Medigap A Through N Explained

Choosing a Medicare supplement plan for your parent would be straightforward if they all covered the same things. They don't. Each Medigap plan fills in a different portion of what Original Medicare leaves unpaid, and the differences between them translate directly into your parent's monthly premium and out-of-pocket costs when they actually need care.

This guide gives you a practical comparison chart, explains what each benefit means in plain English, and tells you which plans most adult children end up choosing for their parents — and why.

Why Your Parent Needs a Supplement Plan at All

Original Medicare (Parts A and B) covers about 80% of approved medical costs. The remaining 20% has no annual cap. A parent who has a serious illness, cancer treatment, or a long hospital stay could face tens of thousands of dollars in cost-sharing with no limit.

Medigap policies are standardized private insurance plans that pay those gaps. They're regulated by the federal government, which means a Plan G from Humana covers the exact same benefits as a Plan G from AARP/UnitedHealthcare. The only differences are the monthly premium and the quality of customer service.

The Medicare Supplement Comparison Chart

The chart below shows which costs each plan covers. "Yes" means the plan pays that cost. "Partial" means it covers a percentage. A blank means the beneficiary pays it themselves.

*Plan C and Plan F are only available to those who turned 65 before January 1, 2020.

**Plan N pays full Part B coinsurance except for copays up to $20 for some office visits and up to $50 for ER visits that don't result in hospital admission.

What Each Benefit Actually Means

Part A hospital coinsurance: After a hospital stay exceeds 60 days, Original Medicare starts charging a daily coinsurance. Without a supplement, your parent pays this every day. All Medigap plans cover this, plus give you an additional 365 hospital days beyond what Medicare provides.

Part B coinsurance: The 20% your parent owes on doctor visits, outpatient procedures, and other Part B services. This is where costs pile up fastest for people who see specialists regularly.

Skilled nursing facility coinsurance: After a qualifying hospital stay, Medicare covers SNF care for up to 100 days, but days 21–100 cost $204.50/day (2025 rate). Most plans cover this; Plans A and B do not.

Part A deductible: $1,632 per benefit period (2025). This isn't annual — your parent can owe it multiple times in a year if they're hospitalized, discharged, and readmitted after 60 days.

Part B deductible: $257 per year (2025). Only Plans C and F cover this, and both are closed to new enrollees.

Part B excess charges: When a doctor doesn't accept Medicare assignment, they can charge up to 15% above Medicare's approved rate. Only Plans F and G cover this. Plan N does not.

Foreign travel emergency: Covers 80% of emergency care abroad after a $250 deductible, up to a lifetime limit of $50,000. Relevant for parents who travel internationally.

The Plans Most Worth Considering

In practice, most adult children helping a parent enroll in Medigap land on one of three plans:

Plan G: The Most Comprehensive Option for New Enrollees

Plan G is the closest to full coverage available today. Your parent pays the $257 Part B annual deductible once per year. After that, the plan covers 100% of Medicare-approved costs — no copays for office visits, no coinsurance for surgeries or hospital stays, no unexpected bills.

This predictability is the reason Plan G is the most popular Medigap plan. It turns healthcare costs into a fixed monthly number: the premium plus $257 once a year. For risk-averse families or parents with ongoing health needs, that ceiling on unpredictable costs is worth the higher monthly premium.

Plan N: The Budget Option for Healthier Seniors

Plan N has a lower monthly premium than Plan G — often $30 to $50 less per month. The trade-off is modest cost-sharing: up to $20 copay for some office visits, up to $50 for ER visits that don't become inpatient admissions.

The more important caveat is Part B excess charges. If your parent's doctor doesn't accept Medicare assignment, Plan N leaves that 15% gap uncovered. Before choosing Plan N, check whether your parent's current doctors accept Medicare assignment. If they do — which most do — Plan N's exposure is limited to those small copays.

Plan N is best for: Healthy, active seniors who see the doctor infrequently and whose providers all accept Medicare assignment.

Plan K and L: The High-Deductible Alternatives

Plans K and L cover only 50% or 75% of most costs until a beneficiary hits an out-of-pocket threshold ($7,220 and $3,610 respectively in 2025), after which the plan pays 100%. These work similarly to a high-deductible health plan and carry lower premiums, but they introduce meaningful financial exposure. They're a niche choice — suitable only for parents who are very healthy, have significant assets to cover the deductible years, and want the lowest possible monthly premium.

How to Compare Medigap Plans in Your Parent's State

The benefits are standardized, but the premiums are not. For the same Plan G, one insurer might charge $120/month while another charges $175/month — for identical coverage.

Step 1: Use Medicare.gov's Medigap plan finder (medicare.gov/find-a-plan) to see every insurer offering Medigap in your parent's ZIP code, with premium estimates.

Step 2: Check how the insurer prices the policy. Ask whether it's attained-age rated (premium rises as your parent gets older), issue-age rated (locked to the age at purchase), or community rated (same price for everyone). Attained-age plans look cheapest at 65 but become the most expensive by age 80.

Step 3: Check financial ratings. AM Best ratings tell you whether the insurer is financially stable. Stick with A-rated carriers.

Step 4: Look at the enrollment window. Your parent has guaranteed issue rights — no health questions, no denial — for the first 6 months after their Part B starts. Outside that window, insurers can deny coverage or charge more based on health history. This window is the most important reason to enroll early.

Medigap Doesn't Include Drug Coverage

None of the Medigap plans above include prescription drug coverage. Your parent needs a standalone Part D plan in addition to their Medigap policy. Use the Medicare Plan Finder at medicare.gov/plan-compare, enter every medication with exact dosages, and sort by total drug plus premium cost.

A Note on Medicare Advantage vs. Medigap

If you're comparing Medigap against Medicare Advantage (Part C), understand the structural difference: Medigap pairs with Original Medicare and gives your parent access to any provider that accepts Medicare nationally, with no network restrictions. Medicare Advantage replaces Original Medicare with a private plan, typically with a network, prior authorization requirements, and an out-of-pocket maximum that can be as high as $9,350 in 2026.

Switching from Medicare Advantage back to a Medigap plan later in life is difficult — insurers can deny or surcharge applicants outside the guaranteed issue window. This makes the initial choice between pathways especially consequential.

Getting Help Comparing Plans

If the chart above raises more questions than it answers, consider these free resources:

• SHIP (State Health Insurance Assistance Program): Free, unbiased counseling from trained volunteers. Find your state's program at shiphelp.org. Appointment wait times extend during fall enrollment season, so call early.
• Medicare.gov: The official comparison tool. Objective and up-to-date with current-year premiums.

Our Medicare Enrollment Guide walks through the full Medigap selection process step by step — including how to evaluate your parent's health profile, compare pricing methods, and navigate the guaranteed issue window before it closes. It's written specifically for adult children managing this process on behalf of a parent.