Medicare provides important health coverage for millions of older Americans, but Original Medicare does not pay for every healthcare expense. Deductibles, coinsurance, copayments, and other costs can still leave retirees responsible for a meaningful portion of their medical bills.
That is where Medicare Supplement Insurance, commonly called Medigap, can help.
Medigap policies are sold by private insurance companies and are designed to work alongside Original Medicare. Depending on the plan you select, a Medigap policy can pay some or most of the out-of-pocket costs that remain after Medicare pays its share.
For retirees who value predictable healthcare expenses and the freedom to visit providers that accept Medicare, Medigap can be an important part of retirement planning.
Here is what you should know about Medicare Supplement Plans, including how they work, what they cover, what they cost, and how to compare your options.
What Are Medicare Supplement Plans?
Medicare Supplement Insurance is additional insurance that helps pay your share of certain healthcare costs under Original Medicare, which consists of Medicare Part A and Part B.
These expenses may include:
- Medicare Part A coinsurance and hospital costs
- Medicare Part B coinsurance or copayments
- The Part A deductible under certain plans
- Skilled nursing facility care coinsurance
- Hospice care coinsurance or copayments
- The first three pints of blood needed for a medical procedure
- Certain emergency medical expenses while traveling outside the United States
Exactly what is covered depends on the Medigap plan you choose.
It is important to understand that Medigap does not replace Original Medicare. Medicare generally pays its portion of an eligible medical bill first, and then your Medigap policy pays according to the benefits included in your policy.
The official Medicare website explains that Medigap policies are designed to help cover out-of-pocket expenses associated with Original Medicare, including certain deductibles, coinsurance, and copayments.
How Medigap Works With Original Medicare
Suppose you receive a Medicare-covered medical service.
Medicare first determines the Medicare-approved amount for that service and pays its portion. Your Medigap policy may then cover some or all of your remaining responsibility, depending on your plan.
This arrangement can make healthcare spending easier to anticipate.
Without supplemental coverage, someone using Original Medicare may have to budget for premiums plus deductibles and coinsurance as medical needs arise. With Medigap, some of those expenses can be shifted into a more predictable monthly insurance premium.
Another major benefit is provider flexibility. Because Medigap works with Original Medicare rather than using a traditional private-plan network, you can generally receive covered care from doctors and providers throughout the United States that participate in Medicare.
Medigap is also different from Medicare Advantage. A Medicare Advantage plan is an alternative way to receive Medicare benefits through a private plan. Medigap supplements Original Medicare. You generally cannot use a Medigap policy to cover Medicare Advantage deductibles or copayments.
Who Can Buy a Medigap Policy?
Generally, you need to be enrolled in both Medicare Part A and Medicare Part B before purchasing Medigap.
For many people, this occurs around age 65.
Federal rules concerning Medigap availability for people under 65 can be different. If you qualify for Medicare because of a disability or certain medical conditions, your ability to purchase Medigap may depend partly on your state’s rules.
That makes timing especially important.
Understanding the Medigap Open Enrollment Period
One of the most important things to understand about Medigap is that its Open Enrollment Period is not the same as Medicare’s annual fall Open Enrollment Period.
Your Medigap Open Enrollment Period is generally a one-time, six-month period beginning when you are 65 or older and enrolled in Medicare Part B.
During this period, you have important federal protections when purchasing a Medigap policy.
Once this enrollment window ends, an insurance company may be permitted to use medical underwriting when you apply unless you qualify for a guaranteed-issue right or have additional protections under state law. That could potentially result in a higher premium or the insurer declining your application.
This is one reason people approaching Medicare eligibility should research Medigap before their enrollment window passes.
Understanding Standardized Medigap Plans
In most states, Medigap policies are standardized and identified by letters.
The standardized plans include:
- Plan A
- Plan B
- Plan C
- Plan D
- Plan F
- Plan G
- Plan K
- Plan L
- Plan M
- Plan N
Massachusetts, Minnesota, and Wisconsin standardize Medigap policies differently.
An important feature of standardization is that the basic benefits of a particular lettered plan are generally the same regardless of which insurance company sells the policy.
For example, the standardized benefits of one company’s Plan G are the same as the standardized benefits of another company’s Plan G.
That does not mean the premiums will be identical.
Insurance companies can charge different prices for the same standardized plan. When comparing policies, therefore, it can be useful to first decide which plan benefits you want and then compare insurers offering that particular plan.
Popular Medigap Options
Although several standardized plans are available, Plan G and Plan N are commonly considered by people becoming eligible for Medicare today.
Medigap Plan G
Plan G provides broad coverage of many of the cost-sharing gaps associated with Original Medicare.
It covers benefits such as the Medicare Part A deductible, Part A hospital coinsurance, skilled nursing facility coinsurance, Part B coinsurance, and Part B excess charges.
However, standard Plan G does not pay the Medicare Part B deductible.
For 2026, the Medicare Part B annual deductible is $283. That means someone with standard Plan G would generally be responsible for satisfying that deductible before applicable Part B coverage begins paying according to Medicare and Medigap rules.
Some states and insurers also offer a high-deductible version of Plan G. In 2026, the high-deductible Plan G amount is $2,950.
Medigap Plan N
Plan N also provides substantial supplemental coverage but requires the policyholder to accept more cost sharing in exchange for what may be a lower premium.
Under Plan N, you can be responsible for a copayment of up to $20 for certain office visits and up to $50 for certain emergency room visits that do not result in an inpatient hospital admission.
Plan N also does not cover Medicare Part B excess charges.
Whether Plan N or Plan G is more appropriate depends on factors such as premium differences, expected healthcare use, and your preference for predictable expenses.
Plans K and L
Plans K and L work differently because they use greater cost sharing.
Rather than covering 100% of several Medigap benefits immediately, these plans cover specified percentages until an annual out-of-pocket limit is reached.
For 2026, Medicare lists the Medigap Plan K out-of-pocket limit as $8,000 and the Plan L limit as $4,000. After you meet the applicable annual limit and the Part B deductible, the Medigap policy pays 100% of covered services for the remainder of the calendar year.
What About Plans F and C?
You may still hear people talk about Medigap Plan F because it historically offered extremely comprehensive coverage.
However, Plans C and F are generally unavailable to people who became newly eligible for Medicare on or after January 1, 2020.
People who were eligible for Medicare before that date may still have access to these plans under certain circumstances.
This distinction is important when researching Medigap online because older articles may recommend Plan F without explaining that many newer Medicare beneficiaries cannot purchase it.
What Medigap Does Not Cover
Medigap can provide significant financial protection, but it should not be confused with comprehensive healthcare insurance that covers every possible expense.
Medigap generally does not cover:
- Routine dental care
- Routine vision care
- Hearing aids
- Eyeglasses
- Long-term custodial care
- Private-duty nursing
- Prescription drugs
Modern Medigap policies do not include outpatient prescription drug coverage. If you want prescription coverage while using Original Medicare, you may need a separate Medicare Part D prescription drug plan.
Long-term care is another important distinction. A Medigap policy should not be treated as a substitute for long-term care planning. Extended custodial care in a nursing facility, assisted living community, or at home can create substantial expenses that generally fall outside Medigap coverage.
How Much Does Medigap Cost?
There is no single national Medigap premium.
Your cost can depend on several factors, including:
- Where you live
- Which standardized plan you choose
- Which insurance company you select
- Your age
- Tobacco use
- Available household or payment discounts
- The insurer’s pricing method
- Whether medical underwriting applies
You pay your Medigap premium directly to the private insurance company in addition to your Medicare Part B premium.
This is important when building a retirement healthcare budget. A Medigap premium should not be viewed in isolation. Consider your total expected healthcare spending, including Medicare premiums, Medigap premiums, prescription coverage, deductibles, and expenses for services that Medicare does not cover.
How Medigap Premiums Are Priced
Insurance companies generally use one of three methods to price Medigap policies.
Community-Rated
With community-rated pricing, the premium generally isn’t based on your age.
A 66-year-old and a 76-year-old purchasing the same policy could therefore pay the same base premium, although premiums can still increase because of inflation and other factors.
Issue-Age-Rated
With issue-age-rated pricing, your premium is based partly on your age when you purchase the policy.
Someone who buys at 65 may therefore start with a lower premium than someone who purchases the same policy at 75.
Your premium does not rise simply because you get older, although it can still increase for other reasons.
Attained-Age-Rated
With attained-age-rated pricing, your premium is based partly on your current age.
These policies can appear inexpensive when you first enroll but may become more expensive as you get older. Premiums can also rise for inflation and other reasons.
Understanding the pricing method is important because the cheapest policy today will not necessarily remain the cheapest policy over a long retirement.
A Simple Medigap Cost Example
Consider a hypothetical retiree named Susan.
Susan is 67 and comparing two Medigap policies with similar benefits for her needs.
One policy costs $150 per month, while another costs $180 per month.
The difference may initially seem small — only $30.
But over one year:
$30 × 12 months = $360
Over five years, assuming for simplicity that premiums never changed:
$360 × 5 = $1,800
Of course, actual Medigap premiums can and often do change over time. But the example demonstrates why comparing premiums matters even when two policies provide the same standardized benefits.
The lowest premium should not automatically determine your decision, either. Consider the insurer’s pricing method, historical rate increases where available, customer service, discounts, and your expected long-term needs.
Medigap and Travel
One reason some retirees choose certain Medigap policies is travel flexibility.
With Original Medicare and Medigap, you generally are not tied to the local provider networks that can apply to some other forms of health coverage. That can be useful for retirees who spend significant time in different states.
Certain Medigap plans also provide limited foreign travel emergency benefits.
However, foreign travel coverage has specific limits and requirements, so frequent international travelers should review the details rather than assuming Medigap provides comprehensive international health insurance.
Can You Change Medigap Plans Later?
You can apply to change Medigap policies, but switching later may not be as simple as changing plans during Medicare’s annual enrollment period.
Outside your initial Medigap Open Enrollment Period or a guaranteed-issue situation, federal law generally does not require an insurer to accept your application. Medical underwriting may apply.
Some states provide additional consumer protections, including special opportunities to switch Medigap plans around a birthday or policy anniversary.
Because rules vary, check the requirements in your state before dropping an existing Medigap policy.
You should generally avoid canceling existing supplemental coverage until you know your replacement coverage has been approved and when it will take effect.
How to Choose the Right Medigap Plan
There is no single Medigap plan that is best for everyone.
Instead, think about how the policy fits your health needs, finances, and retirement lifestyle.
Ask yourself:
- How much can I comfortably spend on premiums each month?
- Would I rather pay a higher premium for more predictable medical expenses?
- How frequently do I visit doctors or specialists?
- Am I comfortable paying occasional copayments?
- Do I travel frequently within the United States?
- Do I spend part of the year in another state?
- Is foreign travel emergency coverage important to me?
- How does the insurer determine future premiums?
- Could I comfortably afford the policy if premiums rise?
- What expenses will I still need to cover separately?
Once you decide which standardized Medigap plan fits your needs, compare the same lettered plan from multiple insurance companies.
Because standardized benefits are generally identical within the same plan letter, premium differences and company characteristics become particularly important.
Medigap as Part of Your Retirement Healthcare Plan
Choosing health coverage is not simply about finding the lowest monthly premium.
Healthcare costs should be considered as part of your larger retirement budget.
You may need to account for Medicare Part B premiums, Medigap premiums, Part D prescription drug coverage, dental and vision expenses, hearing care, long-term care, and other medical costs that Medicare does not fully cover.
For some retirees, paying a higher monthly Medigap premium may be worthwhile because it reduces uncertainty around other Medicare-covered medical expenses.
Others may prefer a plan with a lower monthly premium while accepting additional cost sharing.
The goal is to find a balance that fits both your healthcare needs and your long-term financial resources.
Final Thoughts
Medicare Supplement Insurance can help make healthcare expenses under Original Medicare more manageable and predictable. By covering certain deductibles, coinsurance, copayments, and other gaps, Medigap can reduce the financial uncertainty that sometimes accompanies medical care during retirement.
But choosing a policy requires more than simply selecting the plan with the most benefits.
Consider the monthly premium, how the insurer prices the policy, your expected healthcare use, your ability to handle out-of-pocket expenses, and whether the coverage fits your retirement lifestyle.
Pay particular attention to your Medigap Open Enrollment Period. Missing this important enrollment window can affect your ability to purchase or switch coverage later.
Before enrolling, compare policies available in your area and verify current benefits and costs through Medicare or your State Health Insurance Assistance Program (SHIP). Medicare rules, deductibles, premiums, and plan limits can change from year to year.
Understanding those details before making a decision can help you choose coverage that protects both your health and your retirement finances.
This article is for general educational purposes and is not personalized insurance, financial, or medical advice.
