Navigating the Medigap Maze: Your Ultimate Guide to Supplemental Medicare
Understanding Medicare Medigap plans is important because only 11% of Original Medicare beneficiaries have no supplemental coverage [28]. Medigap insurance helps pay for out-of-pocket costs, such as copayments and deductibles, that Original Medicare doesn’t cover. With options ranging from complete Medigap Plan G to cost-sharing Plans K and L, choosing the right supplemental coverage can affect your healthcare expenses by a lot. The average monthly premium was about $217 in 2023[28], but costs vary by plan type and location. We’ll walk you through everything you need to know about Medigap insurance, including how to compare plans, understand enrollment periods, and select the best coverage for your needs.
What is Medigap insurance, and how does it work?
Medicare supplement insurance fills the financial gaps that Original Medicare leaves behind. Medigap is extra insurance you purchase from private companies to cover out-of-pocket expenses such as copayments, coinsurance, and deductibles that Parts A and B don’t cover.
Understanding Medicare supplement Medigap coverage
You must enroll in both Original Medicare Part A and Part B before buying any Medigap plan[1]. This requirement applies to everyone, without exception. Each policy covers just one person, so married couples need separate policies if both want Medicare Supplemental Insurance [29].
Medigap policies are standardized in most states and labeled with letters such as A, B, D, G, K, L, M, and N [3]. The coverage within each lettered plan remains similar, regardless of which insurance company sells it, though premiums can vary widely between insurers. To name just one example, a 65-year-old nonsmoking man in Fort Myers, Florida, could pay $64.00 per month for Plan K or $263.00 per month for Plan D [30]. A 65-year-old nonsmoking woman in Wichita, Kansas, might pay $32.00 per month for high-deductible Plan G versus $455.00 per month for regular Plan G [30].
Your policy automatically renews each year, even if health problems develop [29]. Insurance companies can drop your coverage under three specific circumstances only: you stop paying premiums, you provided false information on your application, or the company goes bankrupt[29].
How Medigap works with Original Medicare
The payment process follows a straightforward sequence. Medicare pays its share of approved amounts for covered services first. Your medigap policy then pays whatever you owe, according to your plan’s benefits [29].
Most policies arrange direct claims processing with Medicare for Part B services[29]. The insurance company receives your claim information from Medicare automatically and then pays your doctor the amount you owe. Some insurers extend this service to Part A claims as well.
Ask whether your doctors “participate” in Medicare by accepting assignment for all Medicare patients if your insurer doesn’t get claims from Medicare directly[29]. Your Medigap insurance company must pay them directly when doctors participate, and you request it.
Medigap vs Medicare Advantage: Key differences
These two options represent different approaches to Medicare coverage. Medigap supplements Original Medicare, while Medicare Advantage replaces it with private insurance[31].
You can visit any doctor or hospital that accepts Medicare with a Medigap plan[31]. Medicare Advantage plans limit you to network providers. Going out of network either means no coverage or higher copayments[31].
The out-of-pocket maximum for in-network Medicare Advantage care can reach $9,250.00 in 2026[32]. Most medigap plans don’t have maximum limits because they cover the gaps that lead to out-of-pocket costs [33]. Plans K and L are exceptions, with limits of $7,220.00 and $3,610.00 for 2025[33].
Federal law prohibits the use of Medigap with Medicare Advantage [31]. Insurance companies cannot sell you a Medigap policy if you’re enrolled in a Medicare Advantage plan. You have 12 months to return to Original Medicare, with special rights to buy a Medigap policy if you switch from Medigap to Medicare Advantage for the first time [34].
What medigap doesn’t cover matters as much as what it does. These policies exclude prescription drugs, long-term care, vision, dental, hearing aids, eyeglasses, and private-duty nursing[7]. You need a separate Medicare Part D plan for prescription coverage.
Understanding the different Medigap plans available
Ten standardized Medicare Medigap plans exist in most states, each identified by letters: A, B, C, D, F, G, K, L, M, and N [4]. Standardization will provide benefits within each lettered plan that remain similar regardless of which insurance company sells it [4]. Price becomes the variable across policies with the same letter sold by different companies [35].
Medigap Plan G: The most complete option
Plan G accounts for 39% of all Medigap policyholders, covering nearly 5.3 million people in 2023[12]. This plan became the most popular option since Plan F was discontinued for new enrollees. Plan G covers the Part A deductible and all cost sharing for Part A and B covered services, but not the Part B deductible[12]. You get 100% coverage of Part A coinsurance and hospital costs up to an additional 365 days after Medicare benefits end, Part B coinsurance or copayment, the first three pints of blood each year, Part A hospice care coinsurance, skilled nursing facility care coinsurance, the Part A deductible, Part B excess charges, and 80% of foreign travel emergency care up to plan limits[6].
Medigap Plan N: Balancing coverage and affordability
Plan N covers 10% of policyholders, about 1.4 million people[12]. This plan offers lower premiums than Plan G while maintaining solid coverage [36]. Plan N pays 100% of the Part B coinsurance, except for copayments of up to $20.00 for some office visits and up to $50.00 for emergency room visits that don’t result in inpatient admission [6]. The plan covers the Part A deductible but not the Part B deductible or excess charges[6].
Medigap Plan F: Legacy coverage for eligible beneficiaries
Plan F holds the second-largest enrollment share at 36%, covering nearly 4.9 million people [12]. Beneficiaries who became eligible for Medicare before January 1, 2020, can purchase this plan[6]. Plan F provides the most extensive coverage and pays the Part B deductible in addition to all benefits offered by Plan G[6]. This difference makes it the plan that covers 100% of all Medicare supplement insurance benefits.
High-deductible plans F and G
Plans F and G offer high-deductible versions in some states[6]. You must pay Medicare-covered costs, including coinsurance, copayments, and deductibles, up to $2,950.00 in 2026 before your policy pays anything [6][37]. High-deductible Plan F is available to those eligible for Medicare before January 1, 2020. High-deductible Plan G is available if you are new to Medicare on or after that date[37]. These versions provide lower monthly premiums but require meeting the deductible first.
Plans K and L: Lower premiums with cost-sharing
Plans K and L offer lower monthly premiums than other Medigap plans [38]. Plan K covers 50% of Part B coinsurance, blood costs, Part A hospice care coinsurance, skilled nursing facility care coinsurance, and Part A deductible[6]. Plan L covers 75% of the same benefits [6]. After you meet your out-of-pocket yearly limit of $8,000.00 for Plan K or $4,000.00 for Plan L in 2026 and your yearly Part B deductible of $283.00, the plan pays 100% of covered services for the rest of the calendar year[6].
Basic coverage with Plans A, B, D, and M
Plan A covers just basic benefits without the Part A deductible[9]. Plan B adds coverage for the Part A deductible, which could be one of your largest out-of-pocket expenses during hospital stays[9]. Plan D covers almost everything that Plans C, F, and G do but excludes Part B excess charges and the Part B deductible. Plan M covers 50% of the Part A deductible while providing full coverage for other basic benefits[6].
What does Medigap cover, and what are the costs?
Medigap policies address specific financial burdens that Original Medicare leaves uncovered. Medicare Part A creates gaps through hospital deductibles per hospital stay and coinsurance payments for days 61 through 90 of hospitalization. Higher copayments apply for lifetime reserve days 91 through 150. Skilled nursing facility coinsurance covers days 21 through 100[10]. Part B generates expenses through an annual deductible that must be met before Medicare pays for covered services, and a 20% coinsurance payment on all approved charges [10].
Medicare gaps that Medigap addresses
Balance billing is another Part B gap in which physicians charge amounts exceeding Medicare-approved amounts [10]. Medigap plans help cover copayments, coinsurance, and deductibles associated with Original Medicare[7]. Some policies extend coverage to services that Original Medicare excludes entirely. Emergency medical care during foreign travel is one example[7].
Medigap cost comparison across plan types
Premium variations reflect coverage differences across plan types. Plans offering more complete benefits command higher monthly costs. Plan K starts at $66.00 per month for a 65-year-old female nonsmoker in Atlanta, while Plan G begins at $131.00 [11]. High-deductible Plan G offers lower entry costs starting at $44.00 per month[11]. Plan N premiums start at $93.00, and Plan M starts at $94.00 [11].
Average monthly premiums by plan and location
The average medigap premium reached $217.00 in 2023 across all current policyholders[11][12]. Plan G, the most complete option for new enrollees, averaged $164.00 per month but ranged from $140.00 in Washington, D.C., to $236.00 in New York [12]. Plan F premiums among current holders averaged $274.00 and ranged from $214.00 in Vermont to $313.00 in New York[12].
Insurance companies price policies using three methods. Community-rated premiums charge everyone the same amount, regardless of their age. Issue-age-rated premiums lock in rates based on purchase age. Attained-age-rated premiums increase as you age[11].
Out-of-pocket maximums and deductibles
Plans K and L include spending caps. The plan pays 100% of covered services for the calendar year’s remainder after meeting the $8,000.00 out-of-pocket maximum for Plan K or $4,000.00 for Plan L in 2026, plus the yearly Part B deductible of $283.00[6][8]. High-deductible plans require paying $2,950.00 in 2026 before coverage begins[6][11].
What Medigap doesn’t cover
Medigap plans exclude long-term care in nursing homes, vision care, dental services, hearing aids, eyeglasses, and private-duty nursing[7]. Prescription drug coverage requires enrollment in a separate Medicare Part D plan, since Medigap policies sold after 2005 don’t include medication coverage [7].
When and how to enroll in a Medigap plan
The timing of your enrollment determines whether you face medical scrutiny and higher costs. People can apply for Medicare Medigap plans at any time, but coverage varies depending on when you apply [13].
Your six-month Medigap open enrollment period
Your Medigap Open Enrollment Period starts the first day of the month you turn 65 and enroll in Medicare Part B. It lasts six months[14]. Insurance companies must sell you any policy available in your state at the best rate for your age during this window, whatever your health conditions[15]. Your enrollment period begins when that coverage ends if you delay Part B enrollment while you maintain employer coverage with more than 20 employees[16]. Note that you can apply before your Part B effective date, but you need your Medicare number first[16].
Guaranteed issue rights and special enrollment situations
Certain situations provide guaranteed coverage beyond your original period. You qualify if you join a Medicare Advantage plan when first eligible and switch back to Original Medicare within 12 months[17]. Dropping a Medigap policy for Medicare Advantage gives you 12 months to return it [18]. Your plan leaving Medicare, moving outside its service area, or losing employer coverage also gives you guaranteed-issue rights [17]. You have 63 days to apply after coverage ends in most situations[19].
State-specific enrollment rules and birthday provisions
Sixteen states have birthday rules that allow annual plan changes without underwriting [20]. California provides 30 days before and 60 days after your birthday[2]. Oregon allows 31 days, starting on your birthday [2]. Idaho gives 63 days from your birthday[21]. Illinois restricts this to ages 65-75 with 45 days[2]. Louisiana offers 93 days total[2]. Virginia’s rule begins on July 1, 2025, and provides 60 days from your birthday [22].
Medical underwriting after open enrollment
You face medical underwriting in most states if you miss the open enrollment period [14]. Insurance companies can deny coverage, charge higher premiums, or impose six-month waiting periods for preexisting conditions[15]. Four states prohibit such denials: Connecticut, Massachusetts, Maine, and New York[15].
Switching between Medigap plans
You can switch Medigap plans at any time, but acceptance isn’t guaranteed outside protected periods [18]. Don’t cancel existing coverage until your new policy is approved[18].
Choosing the best Medigap plan for your needs
You need to evaluate multiple insurance carriers and use available resources to select the right Medigap plan. Different companies offer varying premiums for similar coverage, so comparison shopping becomes essential.
Comparing AARP Medigap plans and other major insurers
AARP Medicare Supplement Insurance from UnitedHealthcare dominates the market with a 34.8% share and covers over 4.3 million beneficiaries [23]. The company operates in all 50 states plus Washington, D.C., and offers most medigap plan types[23]. AARP members file complaints 40% less often than the industry average[23]. Household discounts range from 10% to 12%, depending on location [23]. But premiums increased by an average of 12% each year over the last three years [23].
Evaluating Humana Medigap plans and Aetna options
Humana provides Plans A through N, with a 6% online enrollment discount available in most states (excluding CA, CT, OH, and PA)[24]. Aetna Medigap plans offer the flexibility to see any doctor who accepts Medicare, without network restrictions[5].
Agent Broker James O’Neal has been helping individuals and families with Medicare insurance at ONealInsuranceGroup.com for over 38 years and can provide guidance on comparing these options.
Using Medicare’s plan finder tool
The Medicare Plan Finder allows side-by-side comparison of up to three plans[25]. The tool displays pricing for Original Medicare, prescription drug plans, Medicare Advantage, and Medicare Supplement policies[25].
Working with State Health Insurance Assistance Programs (SHIP)
SHIP provides free one-on-one counseling through 54 state programs that serve all states and territories[26]. The network has over 12,500 trained team members and assists approximately 4 million beneficiaries each year[27].
Conclusion
Choosing the right Medigap policy requires you to think over coverage needs and budget constraints. Plan G offers the most detailed protection for new Medicare beneficiaries, while Plans K, L, and N provide affordable alternatives with strategic cost-sharing. Purchasing during your six-month open enrollment period guarantees acceptance, regardless of your health status, and secures the best available rates. Agent Broker James O’Neal has been helping individuals and families with Medicare insurance for over 38 years—Quote Plans Online, compare options, and enroll at ONealInsuranceGroup.com, or connect on Facebook, YouTube, and Google Business. Don’t delay your enrollment decision. Securing supplemental coverage now protects you from unexpected medical expenses and provides financial peace of mind throughout your retirement years.
Key Takeaways
Understanding Medigap insurance is essential for Medicare beneficiaries, as these supplemental plans fill critical coverage gaps left by Original Medicare.
• Enroll during your six-month open enrollment period starting when you turn 65 and join Part B to guarantee acceptance regardless of health conditions.
• Plan G offers the most comprehensive coverage for new enrollees, covering all Medicare gaps except the Part B deductible.
• Compare premiums between insurers since standardized plans offer identical benefits but prices vary significantly by company and location.
• Missing your open enrollment window means facing medical underwriting, potential coverage denials, and higher premiums in most states.
• Medigap doesn’t cover prescription drugs, dental, vision, or long-term care—you’ll need separate coverage for these services.
The average monthly premium of $217 in 2023 represents a significant investment, but proper timing and plan selection can save thousands in out-of-pocket medical expenses while providing predictable healthcare costs throughout retirement.
FAQs
Q1. What services does Medicare not cover that I should know about? Medicare doesn’t cover several important healthcare services, including long-term care in nursing homes, most dental care, vision care like eyeglasses, hearing aids, and cosmetic surgery. You’ll need separate insurance or pay out of pocket for these services.
Q2. What are the disadvantages of choosing a Medigap plan? The main drawbacks include paying separate monthly premiums on top of your Medicare Part B premium, purchasing a standalone Part D plan for prescription drug coverage, and potentially facing medical underwriting, with higher costs or coverage denial, if you apply outside your open enrollment period.
Q3. How do healthcare providers view Medigap compared to Medicare Advantage? Doctors generally prefer Medigap because it allows patients to visit any healthcare provider that accepts Medicare without network restrictions, simplifies billing since Medicare pays first and Medigap covers the gaps, and doesn’t require prior authorizations that Medicare Advantage plans often mandate.
Q4. Can I switch from Medicare Advantage back to a Medigap plan? Yes, if you’re switching from Medicare Advantage to Original Medicare for the first time within 12 months of joining, you have guaranteed issue rights to purchase a Medigap policy without medical underwriting. Outside this window, you may face health questions and potential coverage denial in most states.
Q5. What’s the difference between high-deductible and standard Medigap plans? High-deductible Medigap plans (available for Plans F and G) offer lower monthly premiums but require you to pay $2,950 in Medicare-covered costs in 2026 before the plan pays anything. Standard plans have higher monthly premiums but start covering costs immediately after you meet applicable deductibles.
References
[1] – https://www.medicare.gov/health-drug-plans/medigap
[2] – https://www.medicarefaq.com/faqs/medigap-birthday-rule/
[3] – https://www.ncoa.org/article/what-is-medigap/
[4] – https://www.medicare.gov/health-drug-plans/medigap/basics
[5] – https://www.medicare.org/medicare-supplement-plans/aetna/
[6] – https://www.medicare.gov/health-drug-plans/medigap/basics/compare-plan-benefits
[7] – https://www.medicare.gov/health-drug-plans/medigap/basics/coverage
[8] – https://www.cms.gov/medicare/health-drug-plans/medigap/k-l-out-of-pocket-limits-announcements
[9] – https://www.aarpmedicareplans.com/shop/compare/compare-ms.html
[10] – https://medicareadvocacy.org/medicare-info/medigap/
[11] – https://www.nerdwallet.com/insurance/medicare/learn/medigap-cost
[12] – https://www.kff.org/medicare/key-facts-about-medigap-enrollment-and-premiums-for-medicare-beneficiaries/
[13] – https://www.kff.org/medicare/what-to-know-about-the-medicare-open-enrollment-period-and-medicare-coverage-options/
[14] – https://www.medicare.gov/health-drug-plans/medigap/ready-to-buy
[15] – https://www.ehealthinsurance.com/medicare/eligibility/medicare-supplement-plan-and-underwriting/
[16] – https://www.ncoa.org/article/medigap-open-enrollment-period/
[17] – https://www.medicareresources.org/medicare-eligibility-and-enrollment/medicare-special-enrollment-period/
[18] – https://www.kiplinger.com/retirement/medicare/604483/the-rules-for-making-a-medigap-switch
[19] – https://www.aarp.org/medicare/faq/best-time-to-buy-a-medigap-policy/
[20] – https://www.medicareresources.org/medicare-eligibility-and-enrollment/the-birthday-rule-a-gift-to-medigap-enrollees/
[21] – https://boomerbenefits.com/which-states-have-a-medigap-birthday-rule/
[22] – https://www.scc.virginia.gov/media/sccvirginiagov-home/consumer-home/insurance/life-amp-health/senior-resources/medigap-birthday-rule.pdf
[23] – https://www.nerdwallet.com/insurance/medicare/aarp-unitedhealthcare-medicare-supplement-review
[24] – https://www.humana.com/medicare/medicare-supplement-plans
[25] – https://www.cms.gov/newsroom/press-releases/medicare-plan-finder-gets-upgrade-first-time-decade
[26] – http://acl.gov/programs/connecting-people-services/state-health-insurance-assistance-program-ship
[27] – https://www.kff.org/medicare/the-role-of-ships-in-helping-people-with-medicare-navigate-their-coverage/
[28] – https://www.medicareresources.org/medicare-benefits/medigap/
[29] – https://www.medicare.gov/health-drug-plans/medigap/basics/how-medigap-works
[30] – https://www.aarp.org/medicare/guide-to-medigap-plans/
[31] – https://www.aarp.org/medicare/medigap-vs-advantage/
[32] – https://www.nerdwallet.com/insurance/medicare/learn/medigap-vs-medicare-advantage
[33] – https://www.retireguide.com/medicare/compare/medicare-advantage-vs-medigap/
[34] – https://www.medicare.gov/publications/11575-Getting-Started-Medicare-Supplement-Insurance.pdf
[35] – https://www.medicare.gov/health-drug-plans/medigap/basics/costs
[36] – https://boomerbenefits.com/medicare-supplemental-insurance/medicare-supplement-plans/medicare-plan-n/
[37] – https://www.cms.gov/medicare/health-drug-plans/medigap/f-g-j-deductible-announcements
[38] – https://www.humana.com/medicare/medicare-resources/medicare-supplement-plan-costper month for high-deductible Plan G versus $455.00 per month for regular Plan G
