What Is the Best Secondary Insurance with Medicare?
What Is Medicare Supplement Insurance (Medigap)?
Medicare Supplement Insurance, commonly known as Medigap, is private health insurance specifically designed to help fill the coverage gaps that exist in Original Medicare (Parts A and B). While Original Medicare covers a broad range of hospital and medical costs, it does not pay for everything-beneficiaries are responsible for copayments, coinsurance, and deductibles. Medigap policies step in to cover these out-of-pocket expenses, easing the financial burden for seniors and individuals with disabilities.
Medigap is often called the best secondary insurance with Medicare because it pays secondary to Original Medicare. To qualify, you must be enrolled in both Medicare Part A and Part B. Policies are standardized across most states (with specific exceptions in states like Massachusetts and Wisconsin-learn more about Massachusetts Medicare Supplement Plans or Wisconsin Medicare Supplemental Insurance Plans).
Each Medigap plan is identified by a letter (Plan A, B, C, D, F, G, K, L, M, N), and every plan with the same letter must provide the same basic benefits-regardless of the insurance company or your location. However, not all companies offer every Medigap plan, and prices vary by insurer and region.
Key Benefits of Medigap Coverage
- Covers many out-of-pocket costs (copayments, coinsurance, deductibles) for hospital and doctor care.
- Predictable costs-set monthly premiums make budgeting easier.
- No network restrictions-see any provider accepting Medicare nationwide.
- Guaranteed renewability-as long as you pay your premiums, your policy can’t be cancelled due to health changes.
What Medigap Does Not Cover
- Long-term (custodial) care
- Routine vision or dental care
- Hearing aids and routine hearing exams
- Eyeglasses
- Private-duty nursing
Popular and Comprehensive Medigap Plans Explained
Medigap offers several standardized plan options to suit different coverage and budget needs. In 2026, Plan G, Plan F, and Plan N remain the most popular choices nationwide, particularly due to their value in filling key Medicare gaps.
Medigap Plan F
Plan F has historically provided the most comprehensive coverage, paying for almost all out-of-pocket costs you’d otherwise pay under Original Medicare-including the Part B deductible and excess charges. Plan F accounts for over half of all Medigap enrollments in states like California. However, due to changes in federal law, Plan F is only available to people who became eligible for Medicare before January 1, 2020.
Medigap Plan G
Plan G has become the top choice for new Medicare members since 2020. While very similar to Plan F, its only notable difference is that it does not cover the annual Part B deductible (which is $240 in 2025 and likely to increase slightly for 2026). Plan G covers everything else that Plan F does, including Part B excess charges.
Medigap Plan N
Plan N typically offers the lowest premiums among the three, in exchange for some cost-sharing. It covers most costs after you pay your Part B deductible, but you’ll have to pay up to $20 for some office visits and up to $50 for ER visits (if not admitted). Plan N does not cover Part B excess charges, so you may owe extra if you visit providers who charge more than Medicare’s approved amount.
Coverage Across the U.S.
It’s important to remember that standardized Medigap plan benefits are the same regardless of the insurance company or where you live. However, states like Massachusetts and Wisconsin have unique standardization laws. Explore state-specific guidance like the Medicare Supplement Plans Wisconsin: Coverage and Enrollment for precise details.
Medigap Plan G vs Plan F vs Plan N: Detailed Comparison
| Plan | Covers Part B Deductible | Covers Excess Charges | Copays/Coinsurance | Average Monthly Premium* |
|---|---|---|---|---|
| Plan F | Yes | Yes | No cost-sharing | $180-$220 |
| Plan G | No | Yes | No cost-sharing (after Part B deductible) | $166-$178 |
| Plan N | No | No | Office/ER copays apply | $127-$150 |
*Based on 2025 sample premiums for a 65-year-old female nonsmoker in Los Angeles. Your rates may vary significantly by zip code, age, gender, and tobacco use.
Cost-Sharing Explained
- Plan F: Pays all Medicare-approved costs; highest premium but lowest out-of-pocket responsibility.
- Plan G: You only pay the Part B deductible each year; slightly lower premiums than Plan F.
- Plan N: Lower monthly rates, but you pay $20 for office visits, $50 for ER (if not admitted), and possibly excess charges.
Eligibility Differences
Those who first became eligible for Medicare on or after January 1, 2020, are not eligible to buy Plan F or Plan C. For new enrollees, Plan G is the closest available alternative to Plan F in terms of coverage.
Choosing Based on Your Health Needs
Individuals with frequent doctor visits, specialist care, or unpredictable medical expenses may find Plan G or legacy Plan F (if eligible) more cost-effective despite higher premiums. If you’re in good health and don’t see doctors often, Plan N could offer significant savings. Always consider your typical medical usage and tolerance for potential copays and higher out-of-pocket expenses.
How to Choose the Best Medigap Plan for You
Choosing the right Medicare Supplement Insurance depends on various personal factors. Here’s a step-by-step method to help guide your selection for 2026:
- Assess Your Coverage Needs
- Start by considering your current health status, prescription drug usage, and the types of healthcare services you use most.
- Are you comfortable with some out-of-pocket costs in exchange for lower monthly premiums?
- Set a Realistic Budget
- Compare premiums for different plans and consider your potential savings versus your risk for higher out-of-pocket spending with lower-cost plans.
- Remember you’ll pay the Medigap premium in addition to the standard Medicare Part B premium.
- Check Plan Availability
- Not every Medigap plan is offered by every insurer in your state or zip code. UnitedHealthcare, for example, offers a broad range (Plans A, B, C, F, G, K, L, N) in states like California.
- Compare Insurance Company Ratings
- Check stability and customer satisfaction, using metrics like NAIC complaint ratios and A.M. Best financial ratings. For example, State Farm and AARP/UnitedHealthcare have exceptionally low complaint rates in California.
- Look for Additional Perks
- Some companies include optional wellness, vision, hearing, or fitness benefits (like SilverSneakers®), which can be valuable additions.
- Use Your Enrollment Window
- Your best Medigap rates and options are available during your open enrollment period-the first 6 months after you enroll in Part B and are age 65 or older. During this window, you cannot be turned down for coverage or charged more due to health conditions.
- Missed your window? You may face underwriting and higher premiums unless you qualify for special circumstances. Learn more about How to Find Out If I Have Medicare Coverage in 2026.
Comparing Rates and Getting Help
Premiums can vary by up to $100 a month or more for the exact same plan, depending on the insurer and your local market. Always compare quotations from multiple top-rated companies such as Mutual of Omaha, Cigna, BCBS, Aflac, Aetna, and others in your area. For state-specific guides and expert advice, explore resources like How to Get Medicare.
Common Questions About Medigap
Can you have a Medigap plan with a Medicare Advantage plan?
No, you cannot purchase or use a Medigap policy together with a Medicare Advantage (Part C) plan. Medigap only works with Original Medicare (Parts A and B).
Are Medigap benefits standardized?
Yes. All Medigap policies with the same letter (e.g., Plan G) must offer identical basic benefits, regardless of insurer or state (with Massachusetts, Minnesota, and Wisconsin using different standardization models).
Does my Medigap coverage change if I move?
You can keep your Medigap plan if you relocate, but premium rates or plan availability might differ by state. Always notify your insurance provider if you change addresses. If moving to a state with unique Medigap rules, such as Wisconsin or Massachusetts, research your new options in advance.
Can my Medigap policy be canceled?
No, Medigap policies are guaranteed renewable as long as you continue to pay your premiums and provide accurate information. Even if your health deteriorates, your insurer cannot drop your coverage.
What is the difference between Medigap and Medicare Advantage?
Medigap supplements Original Medicare, paying for extra costs like deductibles and coinsurance without network restrictions. Medicare Advantage plans replace Original Medicare and may include additional benefits (e.g., drug coverage, dental), often with network requirements and different cost structures.
When should I enroll in a Medigap plan?
Your initial Medigap enrollment window is the best time: in the 6 months after you’re 65 and enrolled in Part B. During this time, you have guaranteed issue rights and cannot be denied based on health. After this window, you may face medical underwriting.
Key Considerations When Selecting Your Plan
- Guaranteed renewability: Medigap policies cannot be terminated due to health issues if you pay your premium on time and provide truthful application information.
- Premium structure: Monthly Medigap premiums are paid in addition to your Medicare Part B premium. Plans may be priced with attained-age, issue-age, or community-rating methods; ask each insurer how premiums change as you age.
- Standardized benefits: All plans with the same letter offer the same coverage nationwide (except in select states). Comparison shopping focuses on price, service, and available extras.
- Open enrollment period: Enroll when first eligible to avoid medical underwriting, higher premiums, or denial. Premiums can be significantly higher if you enroll later unless you qualify for guaranteed issue rights.
- Provider and hospital choice: Medigap does not use provider networks-any doctor or hospital nationwide that accepts Medicare will also accept your Medigap plan.
- Understand plan changes and state laws: Laws can change-review annual updates and state-specific rules. For instance, check recent updates if comparing Medicare Supplement Plans Wisconsin or Massachusetts Medicare Supplement Plans.
