Medicare Supplement Plans (Medigap) Comparison: Plans A through N Explained
Medicare Supplement Insurance—commonly called Medigap—helps cover healthcare costs that Original Medicare does not pay. This guide provides a clear, literal comparison of Medicare Supplement Plans A through N, explaining exactly what each plan covers, how they differ, and how to choose the right Medigap plan based on coverage needs and cost tolerance.
Key Takeaways
- Medigap plans are standardized and labeled A through N
- All plans cover core Medicare gaps, but benefits vary
- Plan G and Plan N are the most popular choices
- Medigap works only with Original Medicare, not Advantage
- The “best” plan depends on coverage depth vs premium cost
What Medicare Supplement (Medigap) Plans Are
Medigap plans are private insurance policies designed to fill the “gaps” left by Original Medicare (Part A and Part B). These gaps include deductibles, coinsurance, and copayments.
Cause → effect → outcome
Original Medicare leaves cost gaps → Medigap covers those gaps → lower out-of-pocket expenses.
Medigap plans are standardized by the federal government, meaning Plan G offers the same benefits no matter which insurer sells it.
Medicare Supplement Plans A Through N — Full Coverage Comparison
The table below shows exactly which benefits each Medigap plan covers.
Medigap Benefits Comparison Table
| Benefit | A | B | C* | D | F* | G | K | L | M | N |
|---|---|---|---|---|---|---|---|---|---|---|
| Part A coinsurance | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
| Part B coinsurance | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
| Part A deductible | ✖ | ✖ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
| Part B deductible | ✖ | ✖ | ✔ | ✖ | ✔ | ✖ | ✖ | ✖ | ✖ | ✖ |
| Skilled nursing coinsurance | ✖ | ✖ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ |
| Excess charges | ✖ | ✖ | ✖ | ✖ | ✔ | ✔ | ✖ | ✖ | ✖ | ✖ |
| Out-of-pocket limit | ✖ | ✖ | ✖ | ✖ | ✖ | ✖ | ✔ | ✔ | ✖ | ✖ |
*Plans C and F are not available to people newly eligible for Medicare after January 1, 2020.
What Each Medigap Plan Level Means
Plans A and B (Basic Coverage)
- Lowest coverage
- Lower premiums
- Higher out-of-pocket costs
Best for beneficiaries who rarely use healthcare services.
Plans C and F (Most Comprehensive – Legacy Plans)
- Cover nearly all Medicare gaps
- Highest premiums
- Only available to certain beneficiaries
Ideal for those eligible before 2020 who want maximum predictability.
Plan G (Most Popular Choice)
- Covers everything except Part B deductible
- Lower premiums than Plan F
- Strong long-term value
Often considered the best balance of coverage and cost.
Plan N (Lower Premium Alternative)
- Lower monthly premiums
- Small copays for office visits and ER
- No coverage for excess charges
Good for healthy beneficiaries who want savings with manageable cost sharing.
Plans K and L (Cost-Sharing Plans)
- Lower premiums
- Annual out-of-pocket limits
- Partial coverage of many benefits
Designed for those comfortable sharing costs up to a capped limit.
How Much Medicare Supplement Plans Cost
Medigap premiums vary by:
- Age
- Location
- Tobacco use
- Pricing method (attained, issue-age, community-rated)
Typical Monthly Premium Ranges (2025)
| Plan | Typical Monthly Cost |
|---|---|
| Plan A | $90–$150 |
| Plan G | $130–$220 |
| Plan N | $100–$180 |
| Plan F | $160–$260 |
Premiums do not include Part B premiums.
How to Choose the Right Medigap Plan
Decision Framework Table
| If You Want… | Consider This Plan |
|---|---|
| Maximum coverage | Plan G or F |
| Lower premiums | Plan N |
| Predictable costs | Plan G |
| Budget-friendly option | Plan A or K |
| Cost protection with limits | Plan L |
The right choice balances premium cost vs. out-of-pocket risk.
Enrollment Rules You Must Know
- Best time to enroll: Medigap Open Enrollment Period (first 6 months after Part B starts)
- Guaranteed issue rights apply during this window
- Outside this period, medical underwriting may apply
Missing open enrollment can significantly increase costs.
Common Medigap Mistakes to Avoid
- Confusing Medigap with Medicare Advantage
- Overpaying for coverage you don’t use
- Missing open enrollment
- Ignoring excess charge coverage
Frequently Asked Questions
Can I use Medigap with Medicare Advantage?
No. Medigap only works with Original Medicare.
Do Medigap plans include prescription coverage?
No. You need a separate Part D plan.
Is Plan G better than Plan N?
Plan G offers more coverage; Plan N costs less monthly.
Can I switch Medigap plans later?
Yes, but underwriting may apply outside open enrollment.
Are benefits identical across insurers?
Yes. Only premiums and service quality vary.
Action Steps
- Confirm Original Medicare enrollment
- Compare Plans A through N using coverage needs
- Check eligibility for legacy plans
- Compare premiums from multiple insurers
- Enroll during open enrollment if possible
Conclusion
This Medicare Supplement Plans comparison shows that Plans A through N are not interchangeable—each offers a specific balance of coverage and cost. Understanding exactly what each plan covers allows you to choose confidently, avoid unnecessary expenses, and protect yourself from Medicare’s cost gaps in the USA.
