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The Medicare Supplement (Medigap) Plan Comparison Calculator helps Medicare beneficiaries evaluate and compare the 10 standardized supplemental insurance plans designed to cover the gaps in Original Medicare (Part A and Part B), including deductibles, copayments, and coinsurance that beneficiaries would otherwise pay out of pocket. Medigap plans were standardized by the Omnibus Budget Reconciliation Act of 1990 (OBRA 90), which established uniform plan designs designated by letters (A through N) to eliminate consumer confusion caused by insurers offering different benefits under the same plan names. Original Medicare (Parts A and B) covers approximately 80% of approved medical costs, leaving beneficiaries responsible for the remaining 20% coinsurance, various deductibles (the 2024 Part A deductible is $1,632 per benefit period and the Part B deductible is $240 per year), and copayments for specific services. Without supplemental coverage, a single hospitalization or series of medical events can result in thousands of dollars in out-of-pocket costs. Medigap plans fill these gaps by paying some or all of the cost-sharing amounts that Original Medicare does not cover. Plan F was historically the most comprehensive and popular Medigap plan, covering 100% of all gaps in Medicare coverage with no out-of-pocket costs for the beneficiary beyond the monthly premium. However, the Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) prohibited new enrollment in Plan F (and Plan C) for beneficiaries who became newly eligible for Medicare on or after January 1, 2020, because these plans cover the Part B deductible and were deemed to reduce the financial incentive for beneficiaries to use healthcare services judiciously. Plan G has become the most popular plan for post-2020 enrollees, offering identical coverage to Plan F except that the beneficiary pays the $240 annual Part B deductible. Medigap pricing varies significantly by insurer, geographic location, and the pricing method used. Three pricing methods exist: community-rated (same premium for all ages), issue-age-rated (premium based on age at enrollment but does not increase with age), and attained-age-rated (premium increases with age). Most states use attained-age rating, meaning premiums start lower but increase annually as the beneficiary ages. The Medigap Open Enrollment Period — a one-time, six-month window beginning on the first day of the month you are both age 65 or older and enrolled in Part B — provides guaranteed issue rights, meaning insurers must sell you any plan they offer at the best available rate regardless of health status. Outside this period, insurers in most states can apply medical underwriting and deny coverage or charge higher premiums based on health conditions.
Total Annual Medicare Cost with Medigap = Part B Premium + Medigap Premium + Part D Premium + Uncovered Costs Plan G Annual Cost: Medigap premium (varies by insurer, location, age): ~$1,200-$3,600/year Part B deductible (not covered by Plan G): $240/year All other Medicare gaps: $0 (fully covered) Total predictable cost: Part B premium + Medigap + $240 + Part D Plan N Annual Cost: Medigap premium (typically 15-25% less than Plan G): ~$1,000-$2,800/year Part B deductible: $240/year Copays: $20 per office visit, $50 per ER visit (waived if admitted) Part B excess charges: Not covered (potential exposure in non-assignment states) Estimated total: Part B premium + Medigap + $240 + copays + Part D Worked Example — 67-year-old in Ohio, Plan G: Part B premium: $174.70/month ($2,096/year) Plan G premium: $150/month ($1,800/year) Part D premium: $45/month ($540/year) Part B deductible: $240/year Total predictable annual cost: $4,676 Maximum out-of-pocket beyond premium: $240 (Part B deductible only)
- 1Understand what Original Medicare does and does not cover. Medicare Part A covers inpatient hospital stays with a $1,632 deductible per benefit period (2024), skilled nursing facility coinsurance starting at day 21, and hospice. Part B covers outpatient services with a $240 annual deductible and 20% coinsurance on all approved charges after the deductible. Part B does not cap your out-of-pocket spending — there is no annual maximum, meaning a major illness could result in unlimited 20% coinsurance costs. Medigap plans address this potentially unlimited exposure.
- 2Compare the 10 standardized Medigap plans to determine which coverage level meets your needs and budget. Plans are designated by letters A through N, each covering a different combination of gaps. Plan A covers the basic benefits (Part A coinsurance for hospital days 61-90 and lifetime reserve days, Part B coinsurance, blood, and hospice coinsurance). Each subsequent plan adds benefits. Plan G covers everything except the Part B deductible. Plan N covers everything except the Part B deductible, Part B excess charges, and adds small copays for office and ER visits.
- 3Shop premiums from multiple insurance companies within your chosen plan letter. Because plans are standardized, Plan G from one insurer covers exactly the same benefits as Plan G from another insurer — the only differences are the premium, the insurer's customer service and claims processing reputation, and any discount programs offered. Premiums for the same plan letter can vary by 50% or more between insurers in the same area, so comparing at least 5-10 quotes is essential.
- 4Determine the pricing method used by each insurer. Community-rated plans charge the same premium regardless of age (premiums may still increase due to inflation and medical cost trends). Issue-age-rated plans base the premium on your age at enrollment and do not increase solely due to aging (though inflation adjustments still apply). Attained-age-rated plans start with the lowest premiums but increase every year as you age. Over a 20-30 year enrollment period, issue-age and community-rated plans typically result in lower total costs despite higher initial premiums.
- 5Enroll during your Medigap Open Enrollment Period for guaranteed issue at the best available rate. This six-month period begins on the first day of the month you are both 65 or older and enrolled in Medicare Part B. During this window, no insurer can deny you coverage, charge higher premiums, or impose waiting periods for pre-existing conditions based on your health status. If you miss this window, you may face medical underwriting, higher premiums, or denial of coverage in most states.
- 6Consider Plan G versus Plan N as the primary decision point for most new enrollees. Plan G provides the most comprehensive coverage available to post-2020 enrollees (everything except the $240 Part B deductible), with completely predictable costs. Plan N typically costs 15-25% less in premium but adds $20 office visit copays, $50 ER copays (waived if admitted), and does not cover Part B excess charges. For frequent healthcare users, Plan G's higher premium may be offset by lower out-of-pocket costs; for healthy beneficiaries, Plan N may save money overall.
- 7Review your Medigap plan annually and consider switching if a better rate is available. While you have guaranteed issue only during your initial Open Enrollment Period, you can switch between Medigap plans at any time — however, outside the Open Enrollment Period, the new insurer can apply medical underwriting and may deny coverage or charge more based on health conditions. Some states (such as California, Connecticut, and New York) provide additional guaranteed issue rights or continuous open enrollment periods that allow switching without medical underwriting.
This newly eligible beneficiary enrolls in Plan G during the Open Enrollment Period at the best available rate. With excellent health, they secure a competitive premium of $120 per month. Their total annual cost beyond Part B and Part D premiums is $1,680, and the maximum they can spend out-of-pocket on Medicare-covered services is $240 (the Part B deductible). Plan G provides complete financial predictability and protection against catastrophic medical costs.
Plan N saves this beneficiary approximately $260 per year compared to Plan G ($1,540 vs. $1,800 in total gap coverage costs). The savings come from the lower monthly premium, partially offset by $20 copays for 8 doctor visits. However, Plan N does not cover Part B excess charges — in states where doctors can charge up to 15% above the Medicare-approved amount, this could add unexpected costs. In practice, fewer than 3% of providers nationally charge excess fees, making this risk minimal in most areas.
This beneficiary enrolled in Plan F before the 2020 cutoff and is grandfathered in. Plan F covers all Medicare gaps including the Part B deductible, resulting in zero out-of-pocket costs for Medicare-covered services. However, the premium of $195/month is higher than Plan G would cost because Plan F is a closed pool with no new enrollees, causing premiums to rise faster as the enrolled population ages. This beneficiary should periodically evaluate whether switching to Plan G (with medical underwriting if approved) would save money overall.
This beneficiary with chronic conditions generating $80,000 in Medicare-approved charges and two hospitalizations would face enormous cost-sharing without Medigap: two Part A deductibles at $1,632 each ($3,264), plus 20% Part B coinsurance on $60,000+ in outpatient charges ($12,000+). Plan G covers all of this except the $240 Part B deductible, limiting total out-of-pocket to $2,940 versus an estimated $16,000+ without Medigap. This demonstrates the catastrophic protection value of Medigap for high-usage beneficiaries.
State Health Insurance Assistance Programs (SHIPs) provide free, unbiased Medigap counseling to Medicare beneficiaries in every state. SHIP counselors help beneficiaries compare plans, understand pricing methods, identify the best rates from local insurers, and navigate the Open Enrollment Period. SHIP counselors serve approximately 7 million beneficiaries annually and are considered the most reliable source of objective Medigap guidance.
Insurance brokers specializing in Medicare products help beneficiaries select and enroll in Medigap plans, often representing multiple insurers and providing premium comparisons. Brokers are compensated by the insurer (not the beneficiary) and can provide a useful service, though beneficiaries should verify that the broker represents a wide range of companies rather than just one or two.
Healthcare financial planners incorporate Medigap premiums into retirement healthcare cost projections, estimating total lifetime Medicare costs including premiums (Part B, Medigap, Part D), deductibles, copays, and services not covered by Medicare (dental, vision, hearing, long-term care). Average lifetime Medicare out-of-pocket costs for a 65-year-old couple retiring in 2024 are estimated at $315,000, making healthcare the largest retirement expense after housing for most Americans.
CMS (Centers for Medicare and Medicaid Services) publishes the Medicare and You handbook annually with Medigap plan comparison charts and distributes it to all Medicare beneficiaries. This publication, combined with the Medicare Plan Finder tool on Medicare.gov, provides the official government resources for comparing Medigap plans, Part D plans, and Medicare Advantage plans.
Several states provide additional Medigap consumer protections beyond federal requirements.
New York requires continuous open enrollment, meaning beneficiaries can switch Medigap plans at any time without medical underwriting. Connecticut provides an annual 30-day open enrollment period. California provides a guaranteed issue right for Medicare Advantage disenrollees. Massachusetts, Minnesota, and Wisconsin use alternative standardized plan structures that differ from the federal letter designations. Beneficiaries in these states should consult their State Health Insurance Assistance Program (SHIP) for state-specific guidance.
Medigap High-Deductible Plan G is available in some states and carries a lower
Medigap High-Deductible Plan G is available in some states and carries a lower premium in exchange for a $2,800 annual deductible (2024) that the beneficiary must pay before the plan begins covering gaps. The premium is typically 60-70% less than standard Plan G. For healthy beneficiaries who rarely use healthcare services, High-Deductible Plan G can provide catastrophic protection at a significantly lower annual cost, though it shifts more financial risk to the beneficiary in high-utilization years.
Beneficiaries under age 65 who qualify for Medicare due to disability or ESRD
Beneficiaries under age 65 who qualify for Medicare due to disability or ESRD face significant challenges obtaining Medigap coverage. Federal law does not require insurers to sell Medigap to beneficiaries under 65, though approximately 30 states have enacted laws requiring Medigap availability for disabled Medicare beneficiaries. In states without such requirements, under-65 beneficiaries may be unable to purchase Medigap at any price and must rely on Medicare Advantage, Medicaid, or employer coverage to fill gaps in Original Medicare.
| Benefit | Plan A | Plan B | Plan G | Plan K | Plan N |
|---|---|---|---|---|---|
| Part A Coinsurance (days 61-90) | 100% | 100% | 100% | 100% | 100% |
| Part A Deductible ($1,632) | No | 100% | 100% | 50% | 100% |
| Part B Coinsurance (20%) | 100% | 100% | 100% | 50% | 100%* |
| Part B Deductible ($240) | No | No | No | No | No |
| Part B Excess Charges | No | No | 100% | No | No |
| Blood (first 3 pints) | 100% | 100% | 100% | 50% | 100% |
| Skilled Nursing Coinsurance | No | No | 100% | 50% | 100% |
| Foreign Travel Emergency | No | No | 80% | No | 80% |
| Annual OOP Maximum | None | None | None | $7,060 | None |
What is the difference between Medigap and Medicare Advantage?
Medigap supplements Original Medicare (Parts A and B) by paying the cost-sharing gaps, allowing beneficiaries to see any doctor who accepts Medicare nationwide with no network restrictions. Medicare Advantage (Part C) replaces Original Medicare with a private plan that typically includes a network of providers, may offer additional benefits (dental, vision, hearing), and has an annual out-of-pocket maximum. Medigap provides more provider choice and predictable costs but has higher premiums and requires a separate Part D plan. Medicare Advantage often has lower premiums (sometimes $0) but may restrict provider choice and have higher out-of-pocket costs for major medical events.
Can I switch from Medicare Advantage to Medigap?
You can switch from Medicare Advantage back to Original Medicare and apply for Medigap, but outside of certain guaranteed issue situations, the Medigap insurer can apply medical underwriting and may deny coverage or charge higher premiums based on your health. This makes switching difficult for beneficiaries with health conditions. A few states (such as California, Connecticut, and New York) provide guaranteed issue rights for Medicare Advantage disenrollees. At the federal level, you have a guaranteed right to Medigap if you leave a Medicare Advantage plan within the first 12 months of initial enrollment. After that, guaranteed issue depends on state law and specific circumstances.
Why is Plan F more expensive than Plan G?
Plan F premiums are increasing faster than Plan G for two reasons. First, Plan F covers the Part B deductible ($240/year), so its base cost is slightly higher. Second and more importantly, Plan F is a closed pool — no new enrollees have been allowed since January 1, 2020. As the enrolled population ages and becomes sicker, claims increase while no younger, healthier beneficiaries enter the pool to offset costs. This aging-in-place effect will cause Plan F premiums to continue rising faster than Plan G, which remains open to new enrollees. Many Plan F beneficiaries are now paying $200-$350/month, while comparable Plan G premiums are $120-$200/month.
What are Part B excess charges?
Part B excess charges occur when a healthcare provider who does not accept Medicare assignment charges up to 15% above the Medicare-approved amount for a service. Only Plan F and Plan G cover excess charges (Plan N does not). In practice, the risk is minimal — over 97% of providers nationwide accept Medicare assignment, and some states (Connecticut, Massachusetts, Minnesota, New York, Ohio, Pennsylvania, Rhode Island, and Vermont) prohibit excess charges entirely. In states that allow excess charges, the exposure is limited to 15% of the Medicare-approved amount for services from non-participating providers.
When is the best time to buy Medigap?
The best time to buy Medigap is during your initial Open Enrollment Period — the six-month window beginning the first day of the month you are both 65 or older and enrolled in Part B. During this period, you have a federal guaranteed issue right to buy any Medigap plan sold in your state at the best available rate, regardless of health conditions. No insurer can charge you more, deny coverage, or impose pre-existing condition waiting periods. After this window closes, you are subject to medical underwriting in most states. Some beneficiaries delay Part B enrollment (because they have employer coverage) and should note that their Medigap Open Enrollment Period begins when they eventually enroll in Part B, not when they turn 65.
Does Medigap cover prescription drugs?
No, Medigap plans sold after January 1, 2006, do not include prescription drug coverage. Beneficiaries who want drug coverage must enroll in a separate Medicare Part D prescription drug plan. Some older Medigap policies sold before 2006 may include drug coverage, but beneficiaries with those plans cannot also enroll in Part D. Beneficiaries should carefully compare the drug coverage and premiums of available Part D plans using the Medicare Plan Finder tool on Medicare.gov during the annual Open Enrollment Period (October 15 through December 7).
プロのヒント
Before selecting a Medigap plan, request premium quotes from at least 5-10 insurers for the same plan letter and specifically ask about the pricing method (community-rated, issue-age, or attained-age). Premiums for the same Plan G can vary by 50% or more between insurers in the same ZIP code. Community-rated and issue-age plans have higher starting premiums but lower long-term costs compared to attained-age plans. Also check insurer financial ratings (A.M. Best, Standard and Poor's) to ensure the company is financially stable enough to pay claims reliably for decades.
ご存知でしたか？
Medigap standardization was driven by a scandal in the 1980s and early 1990s when insurers sold duplicative, confusing, and sometimes worthless Medicare supplement policies to vulnerable seniors. Congressional investigations revealed that some elderly beneficiaries were paying premiums on 5-10 different overlapping policies, none of which they fully understood. The Medigap Simplification provisions of OBRA 1990 reduced the market from hundreds of non-standard plans to 10 standardized designs, making comparison shopping possible for the first time and saving consumers an estimated $1 billion per year in unnecessary premiums.