Medicare Supplement Insurance, also called Medigap, helps people with Original Medicare pay certain out-of-pocket costs such as coinsurance, copayments, and deductibles. Medigap policies are sold by private insurance companies, and standardized plans with the same letter generally provide the same basic benefits regardless of the insurer.
Medigap is designed to supplement Original Medicare, which consists of Medicare Part A and Part B.
A Medigap policy can help pay certain costs that Original Medicare doesn't fully cover. Generally, a person must have Medicare Part A and Part B to purchase a Medigap policy.
Medigap is different from Medicare Advantage. A person generally can't have a Medigap policy and a Medicare Advantage plan at the same time.
Medigap plans are standardized by letter in most states. This means a Plan G policy from one insurer generally provides the same basic benefits as Plan G from another insurer.
The major difference between policies with the same letter is often the premium and insurer-specific pricing. Medicare recommends comparing policies with the same plan letter when evaluating costs.
Premiums can vary significantly between insurers, and premiums typically increase over time.
Plan G provides extensive coverage for many Medicare-covered cost-sharing requirements.
For people who became eligible for Medicare after January 1, 2020, Plan G is one of the standardized Medigap plans that can provide broad coverage while leaving the Medicare Part B deductible as a responsibility.
Plan G also has a high-deductible version in some states. In 2026, the high-deductible Plan G version requires the policyholder to pay up to $2,950 in Medicare-covered costs before the policy begins paying covered benefits.
Potential considerations include:
Plan G can therefore be useful to compare for people who prioritize extensive supplemental coverage and are comfortable paying the applicable premium.
Plan N has a different cost structure from Plan G.
Medicare states that Plan N covers 100% of Part B coinsurance, but beneficiaries can have copayments of up to $20 for certain office visits and up to $50 for emergency-room visits when they aren't admitted as an inpatient.
This cost-sharing structure can make Plan N worth comparing with Plan G when premium differences are significant.
Important factors include:
Because Plan N can involve additional copayments, comparing the annual premium difference with potential out-of-pocket costs can provide a clearer picture of total expenses.
Plan K has a substantially different structure from Plans G and N.
In 2026, Plan K has an annual out-of-pocket limit of $8,000. After meeting the applicable out-of-pocket limit and the annual Part B deductible, the plan pays 100% of covered services for the remainder of the calendar year.
Plan K generally involves more cost-sharing before the annual limit is reached.
Key considerations include:
Plan K can therefore be evaluated differently from plans that provide more extensive first-dollar coverage.
| Feature | Plan G | Plan N | Plan K |
|---|---|---|---|
| Basic Medigap benefits | Extensive | Extensive with cost-sharing | Cost-sharing structure |
| Part B deductible | Generally not covered | Generally not covered | Generally not covered |
| Office-visit copays | Generally no Plan N-style copay | Up to $20 in specified situations | Cost-sharing applies |
| ER copay | Generally no Plan N-style copay | Up to $50 in specified situations | Cost-sharing applies |
| 2026 out-of-pocket limit | No standard annual limit like Plan K | No standard annual limit like Plan K | $8,000 |
| High-deductible version | Available in some states | No | No |
| Premiums | Vary by insurer/location | Vary by insurer/location | Vary by insurer/location |
The exact benefits should always be confirmed against the current policy documents and state-specific rules.
Medicare does not pay the premium for a Medigap policy. The policyholder generally pays the private insurance company a separate monthly premium in addition to the Medicare Part B premium.
Premiums can vary based on factors such as:
Medicare notes that premiums can increase over time.
Not every Medigap plan is sold in every state, and not every insurance company sells every plan.
Massachusetts, Minnesota, and Wisconsin also standardize Medigap policies differently from most other states.
This means a comparison based on national information may not accurately reflect the plans or prices offered in a particular state.
The Medigap Open Enrollment Period is particularly important.
Under federal rules, it is a 6-month period that starts when a person is 65 or older and enrolled in Medicare Part B.
During this period, a person can generally buy any Medigap policy sold in the state, and insurers can't use medical underwriting to deny coverage or change the price because of pre-existing health problems.
This period is different from the annual Medicare Open Enrollment period.
It does not automatically repeat every year.
After the initial Medigap Open Enrollment Period, federal protections can be more limited.
In many situations, an insurer may be able to use medical underwriting or charge a different premium unless a person has a guaranteed issue right or another applicable protection. State laws can provide additional opportunities.
For this reason, timing can be an important consideration when evaluating Medigap coverage.
Changing Medigap policies is not always straightforward.
Under federal law, there generally isn't an unrestricted right to switch Medigap policies at any time. Guaranteed issue rights and certain special circumstances can create additional opportunities.
A person considering a switch should check eligibility, state rules, underwriting requirements, and the new policy's premium before cancelling an existing policy.
Plan F remains an important part of Medigap comparisons, but not everyone can buy it.
Medicare states that eligibility for Plans C and F depends on when a person first became eligible for Medicare. People who were new to Medicare on or after January 1, 2020 generally can't buy these plans.
For people newly eligible for Medicare, Plan G is therefore one of the major comprehensive Medigap plans to compare.
Monthly premiums alone don't tell the whole story.
A useful comparison can include:
Annual premium + expected cost-sharing + deductibles + other applicable expenses
For example, a policy with a lower monthly premium could involve greater cost-sharing when medical services are used.
Conversely, a higher-premium plan may provide more predictable expenses for covered Medicare services.
Actual costs depend on healthcare use and the specific policy.
When evaluating Plan G, consider:
Because Plan G generally has broad benefits, the premium may be higher than some plans with more cost-sharing.
For Plan N, compare:
The premium difference between Plan N and Plan G can be an important part of the calculation.
Plan K requires a different approach because of its cost-sharing structure.
Consider:
The annual limit can be particularly important when evaluating the potential maximum cost exposure.
There is no single Medigap plan that is appropriate for every Medicare beneficiary.
A comparison can begin with several questions:
A person who prefers more predictable cost-sharing may focus on plans with broader benefits.
A plan with greater cost-sharing may have a different premium structure.
Expected healthcare utilization can affect the practical cost difference between plans.
Plan availability and pricing vary by state.
Timing can affect underwriting and the ability to purchase particular policies.
Once a plan letter has been selected, compare insurers offering that same letter.
Medicare states that the benefits for a given standardized plan letter are the same, while premiums can differ significantly between companies.
Useful comparison factors include:
Before purchasing a Medigap policy, consider asking:
Before selecting a policy, review:
Plan letter
Monthly premium
Annual premium
Part B deductible
Copayments
Coinsurance
Out-of-pocket limit
State availability
Insurer pricing
Premium increase history
Open Enrollment status
Guaranteed issue rights
Switching rules
Available discounts
Plans G, N, and K have different benefit and cost-sharing structures and are useful plans to compare. The appropriate choice depends on individual circumstances rather than a universal ranking.
Availability depends on eligibility and state rules. Plan G is one of the standardized Medigap plans, but the ability to purchase a policy can depend on enrollment status and other circumstances.
Yes. In 2026, Medicare states that Plan N can require up to $20 for certain office visits and up to $50 for emergency-room visits when the beneficiary isn't admitted as an inpatient.
The 2026 Plan K out-of-pocket limit is $8,000. After meeting the applicable limit and annual Part B deductible, Plan K pays 100% of covered services for the remainder of the calendar year.
No. Premiums can vary significantly between insurers, even for the same standardized plan letter.
There isn't a universal list of three Medicare Supplement plans that are objectively "worth the cost" for everyone in 2026.
Plan G, Plan N, and Plan K have substantially different coverage and cost-sharing structures and can therefore be useful points of comparison. Plan G generally emphasizes broad supplemental coverage, Plan N combines coverage with specified copayments, and Plan K uses more cost-sharing alongside an annual out-of-pocket limit.