Medicare Supplement (Medigap) plans help cover the 20% of costs that Original Medicare doesn't pay. This guide compares all Medigap plans, average costs, best insurance companies, and enrollment rules for 2025.
Medicare Supplement Quick Facts 2025
- Most popular plans: Plan G and Plan N
- Average cost: $100 - $300/month (varies by age/location)
- Best enrollment time: Medigap Open Enrollment (first 6 months on Medicare Part B)
- Standardized: Same benefits regardless of insurance company
- Works with: Original Medicare only (not Medicare Advantage)
Medicare Supplement Plans Comparison
| Benefit | Plan G | Plan N | Plan F* |
|---|---|---|---|
| Part A Coinsurance | 100% | 100% | 100% |
| Part B Coinsurance | 100% | 100%** | 100% |
| Part A Deductible ($1,632) | 100% | 100% | 100% |
| Part B Deductible ($240) | No | No | 100% |
| Part B Excess Charges | 100% | No | 100% |
| Foreign Travel Emergency | 80% | 80% | 80% |
| Avg. Monthly Premium | $140-$200 | $100-$150 | $180-$250 |
*Plan F only available to those eligible for Medicare before Jan 1, 2020. **Plan N has up to $20 copay for office visits, $50 for ER.
Best Medicare Supplement Plans 2025
Plan G - Best Overall
- Coverage: Covers everything except Part B deductible ($240/year)
- Average cost: $140 - $200/month
- Best for: Most people - comprehensive coverage, predictable costs
- Why choose: Lowest total costs for frequent healthcare users
- Downside: Higher premium than Plan N
Plan N - Lower Premiums
- Coverage: Similar to G, but with small copays
- Average cost: $100 - $150/month
- Copays: Up to $20 office visits, $50 ER (if not admitted)
- Best for: Healthy people who don't see doctors often
- Why choose: Save $40-50/month on premiums
- Downside: Doesn't cover Part B excess charges
Average Medicare Supplement Costs by Age
| Age | Plan G | Plan N | Plan F |
|---|---|---|---|
| 65 | $120 - $170 | $90 - $130 | $160 - $220 |
| 70 | $150 - $210 | $110 - $160 | $190 - $260 |
| 75 | $180 - $260 | $140 - $200 | $230 - $320 |
| 80 | $220 - $320 | $170 - $250 | $280 - $400 |
| 85+ | $280 - $400 | $220 - $320 | $350 - $500 |
Rates vary significantly by state, gender, tobacco use, and insurance company.
Top Medicare Supplement Companies
- AARP/UnitedHealthcare: Largest market share, wide availability
- Blue Cross Blue Shield: Strong regional presence, trusted brand
- Mutual of Omaha: Competitive rates, good customer service
- Cigna: Household discount available
- Aetna: Part of CVS Health, good network
- Humana: Competitive pricing in many states
When to Enroll in Medigap
Medigap Open Enrollment Period
- When: 6-month period starting the month you turn 65 AND are enrolled in Part B
- Why it matters: Guaranteed issue - can't be denied or charged more for health conditions
- After OEP: Companies can deny coverage or charge higher rates based on health
- Exception: Some states have additional guaranteed issue rights
Medigap vs Medicare Advantage
| Factor | Medigap | Medicare Advantage |
|---|---|---|
| Monthly Premium | $100-$300+ | $0-$50 (most) |
| Out-of-Pocket Costs | Very low | Can be high (up to $8,850) |
| Doctor Choice | Any Medicare doctor | Network restrictions |
| Referrals Needed | No | Often yes (HMO) |
| Extra Benefits | No | Yes (dental, vision, hearing) |
| Best For | Travel, chronic conditions | Healthy, budget-conscious |
How to Choose a Medigap Plan
- Assess your health: Frequent doctor visits favor Plan G
- Consider travel: Medigap works nationwide
- Compare premiums: Same coverage, different prices by company
- Check rate increases: Ask about historical premium increases
- Review rating type: Attained-age, issue-age, or community-rated
- Look for discounts: Household, non-smoker, autopay
FAQ
Can I switch Medigap plans later?
Yes, but outside Open Enrollment you may need to pass medical underwriting. Some states offer guaranteed issue for switches.
Does Medigap cover prescriptions?
No. You need a separate Part D plan for prescription drug coverage.
Can I have Medigap and Medicare Advantage?
No. Medigap only works with Original Medicare. You must choose one or the other.
What's the difference between Plan F and Plan G?
Plan F covers the Part B deductible ($240/year); Plan G doesn't. Plan G usually costs less overall because the premium savings exceed $240.