Published on November 26, 2025

Your Complete Guide to Medicare Supplements

When you retire, having a predictable budget is essential. While Original Medicare covers a large portion of your healthcare bills, it leaves behind unpredictable out-of-pocket costs that can make budgeting a challenge. One major hospital stay or a series of specialist visits could leave you with significant expenses. If you value financial peace of mind, a Medicare Supplement plan might be the right choice for you. These plans, also called Medigap, help pay for the deductibles and coinsurance that Medicare doesn’t cover. By paying a set monthly premium for one of these medicare supplements, you can virtually eliminate most of your other medical bills, making your healthcare spending stable and easy to plan for.

Key Takeaways

  • Fill the gaps in Original Medicare: A Medigap plan helps pay for your share of costs, like deductibles and coinsurance, but it doesn’t cover everything. You will still need a separate Part D plan for prescriptions and other policies for routine dental or vision care.
  • Use your Open Enrollment Period wisely: Your one-time, six-month window when you first get Part B is your golden ticket. It guarantees you can buy any plan without answering health questions, a protection you lose once the period ends.
  • Focus on price and reputation: Since all plans with the same letter offer identical basic benefits, your decision should be based on comparing monthly premiums and researching the insurance company’s history of rate stability and customer service.

What is Medicare Supplement Insurance (Medigap)?

If you’ve ever heard the term “Medigap,” you’re already on the right track. Medicare Supplement Insurance, or Medigap, is a type of private insurance policy designed to help cover costs that Original Medicare (Part A and Part B) doesn’t pay for. Think of it as a way to fill in the financial “gaps” in your coverage, making your healthcare expenses much more predictable.

When you have Original Medicare, you’re still responsible for certain out-of-pocket costs like deductibles, copayments, and coinsurance. These expenses can add up quickly, especially if you need frequent medical care or have a hospital stay. A Medigap plan helps pay for its share of these costs after Medicare pays its portion.

These plans are sold by private insurance companies but are standardized by the federal government. This is a key feature because it means that a Plan G from one company must offer the same basic benefits as a Plan G from another company. The main differences you’ll find are in the monthly premium and the company’s customer service. It’s an extra layer of coverage that works alongside your Original Medicare to give you more complete financial protection.

How Medigap and Original Medicare Work Together

Medigap plans are designed to be a partner to your Original Medicare coverage, not a replacement for it. To purchase a Medigap policy, you must first be enrolled in both Medicare Part A and Part B. Once you have a plan, the process is straightforward. When you receive medical care, Medicare pays its approved amount first. Then, your Medigap plan steps in to pay its portion of the remaining costs, like your coinsurance or deductible. It’s important to know that Medigap policies only work with Original Medicare. You cannot have a Medigap plan and a Medicare Advantage (Part C) plan at the same time, as they are two different ways to receive your Medicare benefits.

What Costs Does Medigap Cover?

The primary job of a Medigap plan is to cover your share of costs that Original Medicare leaves behind. Depending on the specific plan you choose (they are labeled with letters like A, G, N, etc.), your policy can help pay for a variety of expenses. Most plans offer basic benefits that include your Part A hospital coinsurance and give you an extra 365 days of hospital care after your Medicare benefits are used up. They also typically cover your Part B coinsurance or copayments, which is usually the 20% of the bill you’d otherwise pay for doctor visits and other outpatient services. Some plans also cover your Part A deductible, skilled nursing facility care, and even medical care needed during foreign travel.

Who Can Get a Medicare Supplement Plan?

Thinking about a Medigap plan is a great step toward managing your health care costs, but first, let’s make sure you’re eligible. The rules are fairly straightforward, and understanding them will help you know exactly when and how to act. For most people, eligibility is tied to turning 65 and enrolling in Original Medicare. However, there are also specific situations for those who qualify for Medicare at a younger age.

The most important thing to remember is that timing is everything. There’s a key window of time when you can buy any Medigap policy sold in your state without having to answer a single health question. Missing this window can make it more difficult or expensive to get a plan later on. We’ll walk through the requirements for those turning 65 and for those who are younger, so you can feel confident about your next steps.

Meeting Age and Enrollment Requirements

To purchase a Medigap plan, you first need to be enrolled in Original Medicare, which means you have both Part A (hospital insurance) and Part B (medical insurance). The best time to buy your policy is during your 6-month Medigap Open Enrollment Period. This period automatically starts on the first day of the month you turn 65 and are enrolled in Part B. Think of this as your golden ticket—during these six months, an insurance company cannot use your health history to deny you a policy or charge you more. You have guaranteed issue rights to buy any plan available in your area.

Special Rules for Eligibility Under 65

What if you’re under 65 but have Medicare due to a disability? You might still be able to get a Medigap plan. While federal law doesn’t require insurance companies to sell Medigap policies to people under 65, many states have their own rules that create opportunities for you. The availability of plans, the cost, and the enrollment windows can vary significantly depending on where you live. Some states offer a limited selection of plans, while others provide more robust options. If you fall into this category, it’s a good idea to research your specific state’s regulations to understand your Medicare Supplement eligibility and find the right coverage.

What Are the Different Medigap Plan Types?

When you start exploring Medigap, you’ll notice that the plans are named with letters. This is part of a system designed to make comparing them much simpler.

An Overview of Plans A Through N

In most states, you can choose from Plans A, B, D, G, K, L, M, and N. The federal government standardizes these plans, which is great news for you. It means that a Plan G from one insurance company offers the exact same basic benefits as a Plan G from any other company. This rule makes it much easier to compare your options without getting lost in the fine print. You may have also heard of Plans C and F, but they are only available to people who were eligible for Medicare before January 1, 2020. For everyone else, the other lettered plans are your choices.

A Look at the Most Popular Plans

With several letters to choose from, it helps to know where most people land. For new Medicare members, Plan G and Plan N are often the most popular choices, and for good reason. Plan G is known for its comprehensive coverage; it pays for nearly all the gaps in Original Medicare once you’ve met your annual Part B deductible. Plan N is another favorite, typically offering a lower monthly premium. In exchange, you’ll pay small copays for certain doctor visits and emergency room trips. These two plans often provide a great balance of coverage and cost, but the right one for you will depend on your personal health and financial situation.

How to Compare Plan Benefits

Since all plans with the same letter offer the same basic benefits, your decision really comes down to two things: cost and company. The only difference between a Plan G sold by Company X and one sold by Company Y is the price they charge. Your job is to find the most competitive premium for the plan letter you want. It’s also wise to consider the insurance company’s reputation for customer service and rate stability over time. You can get Medigap basics and see a chart that shows exactly what each plan covers, making it simple to see the differences between, say, a Plan G and a Plan N side-by-side.

When Is the Best Time to Enroll in a Medigap Plan?

When it comes to Medigap, timing is everything. Choosing the right moment to sign up is just as important as picking the right plan. Enrolling at the right time gives you the most options and protects you from being denied coverage or charged higher premiums because of your health history.

This is because you have a special, one-time window when you first become eligible for Medicare where insurance companies must accept your application. Missing this window can make it much harder, and potentially more expensive, to get a Medigap plan later on. Let’s walk through the key enrollment periods so you can make a confident and timely decision.

Your Medigap Open Enrollment Period

Think of your Medigap Open Enrollment Period as your golden ticket. This is a six-month window that starts on the first day of the month you are both 65 or older and enrolled in Medicare Part B. During this specific timeframe, you have the absolute right to buy any Medigap policy sold in your state. An insurance company cannot use your health history as a reason to deny you coverage or charge you more than anyone else. This is a one-time opportunity, and once it’s over, it doesn’t come back. That’s why it’s so important to understand the Medigap basics before this period begins.

Understanding Your Guaranteed Issue Rights

Your “guaranteed issue rights” are the protections that make your Open Enrollment Period so powerful. These rights mean that during this window, an insurance company must sell you a Medigap plan. They can’t ask you health questions or perform medical underwriting, which is the process they use to evaluate your health risks. This is especially crucial if you have pre-existing conditions. Outside of this protected period, an insurer could review your medical history and decide not to cover you. Understanding your Medicare Supplement eligibility and these rights ensures you can secure the coverage you need without any hurdles.

Applying Outside of Your Enrollment Window

What happens if you miss your six-month Open Enrollment Period? You can still apply for a Medigap plan, but the rules change completely. If you apply outside of your initial window, an insurance company is generally allowed to use medical underwriting. This means they can require you to answer health questions and can review your medical records. Based on your health status, they could legally charge you a higher premium or even deny your application altogether. There are some special situations that might grant you guaranteed issue rights later on, but for most people, the initial enrollment period is the best and simplest time to get a policy.

How Much Do Medigap Plans Cost?

One of the first questions on everyone’s mind is, “How much will this cost me?” The answer isn’t a single number, because the price of a Medigap plan can vary quite a bit. Medigap plans are sold by private insurance companies, and each company sets its own monthly premium.

It’s important to remember that Medigap plans are standardized. This means that a Plan G from one company has the exact same basic benefits as a Plan G from another company. The main differences you’ll find are the price and the company’s customer service. Let’s look at the factors that determine what you’ll pay.

What Affects Your Monthly Premium?

Your monthly premium is the amount you pay to the insurance company to keep your Medigap plan active. Several factors influence this cost, which is why getting a personalized quote is so important.

Companies look at a few key things when setting your premium. Your location plays a big role, as costs can differ from one state or even one zip code to another. Your age, gender, and whether you use tobacco can also affect your price. Generally, you’ll find the lowest premiums when you first become eligible at 65. The specific plan you choose matters, too; a plan with more comprehensive coverage will naturally have a higher premium than one with more basic benefits.

How Insurance Companies Price Plans

To understand how your premium might change over time, it helps to know how insurance companies price, or “rate,” their plans. There are three main ways they do this:

  • Community-rated: Everyone who has the policy pays the same monthly premium, regardless of their individual age. Premiums may still go up because of inflation and other factors, but not just because you get older.
  • Issue-age-rated: Your premium is based on your age when you first buy the policy. It won’t increase just because you have a birthday, but it can rise for other reasons, like overall healthcare cost increases.
  • Attained-age-rated: Your premium is based on your current age, so it will increase as you get older. These plans usually start with lower premiums but will cost more over time.

Knowing which pricing method a company uses can help you anticipate future costs and make a more informed decision for the long term.

Why Your Rates Might Increase Over Time

It’s a common misconception that your Medigap premium will stay the same forever. In reality, you should expect your rate to increase over time. These adjustments aren’t random; they’re typically due to a few predictable reasons.

First, inflation and the rising cost of healthcare in general can cause rates to go up for everyone. If you have an attained-age-rated policy, your premium will also increase as you get older. Beyond that, insurance companies periodically review their claims experience and may adjust rates for an entire group of policyholders. In fact, a recent analysis showed that many companies implemented double-digit rate increases for popular plans in a single year. This is a normal part of the insurance cycle, but it’s something to be prepared for when you budget for your healthcare costs.

What Doesn’t Medigap Insurance Cover?

Medigap plans are fantastic for filling the cost-sharing gaps in Original Medicare, like deductibles and coinsurance. But it’s just as important to understand what they don’t cover so you can plan accordingly and avoid unexpected bills. The simplest way to think about it is this: Medigap is designed to supplement Original Medicare Parts A and B. If Original Medicare doesn’t cover a service in the first place, your Medigap plan generally won’t cover it either. This is a fundamental rule that helps clear up a lot of confusion about what you can expect from your coverage. It ensures you’re not paying for a policy under false assumptions about what it can do.

This means you’ll need to find other ways to pay for some key healthcare expenses. The most common services that fall outside of Medigap coverage are prescription medications you take at home, long-term custodial care, and routine check-ups for your eyes, teeth, and ears. Knowing these limitations ahead of time is empowering. It allows you to build a complete healthcare plan that truly meets all of your needs without any surprises down the road. Let’s look at each of these categories more closely so you can feel confident in your decisions.

Prescription Drugs

One of the most important things to know is that Medigap policies generally do not cover prescription drugs. If you need help paying for your medications, you’ll want to enroll in a separate Medicare drug plan (Part D). This is a separate policy you purchase from a private insurance company that works alongside your Original Medicare and Medigap plan. It’s crucial to sign up for a Part D plan when you first become eligible for Medicare to avoid a permanent late enrollment penalty. Even if you don’t take many prescriptions now, having a plan in place can protect you from high costs in the future.

Long-Term Care

Another area Medigap doesn’t touch is long-term care. This includes non-medical or custodial care you might need if you have a chronic condition, such as help with daily activities like bathing, dressing, or eating. Medigap policies do not cover services like care in a nursing home or from a home health aide for personal care. These services fall under a different category of health planning, and many people explore separate long-term care options to prepare for these potential needs. Medigap is there for your medical bills covered by Medicare, not for ongoing custodial support.

Routine Vision, Dental, and Hearing

While Medicare might cover a diagnostic eye exam if you have glaucoma, it doesn’t cover routine care. Medigap policies follow suit and generally do not cover routine vision or dental care, hearing aids, or private-duty nursing. This means services like your annual eye exam for glasses, dental cleanings and fillings, and the cost of hearing aids won’t be paid for by your Medigap plan. Because these aren’t services covered by Original Medicare, there are no “gaps” for Medigap to fill. Many people choose to buy separate, standalone vision and dental plans to cover these routine expenses.

How to Choose the Right Medigap Plan for You

With ten standardized plans offered by dozens of private insurance companies, picking the right Medigap policy can feel like a monumental task. But it doesn’t have to be. By breaking the process down into a few manageable steps, you can find a plan that fits your health needs and your budget without all the stress.

The key is to think of this as a matching game. You’re looking for the plan that best aligns with your personal situation. It’s not about finding the one “best” plan, but rather the best plan for you. Let’s walk through how to find your perfect match.

Assess Your Healthcare Needs

Before you start looking at plan letters and premium quotes, take a moment to think about your own health. Are you in excellent health and rarely see a doctor outside of annual checkups? Or do you have a chronic condition that requires frequent specialist visits? Consider your family health history and your comfort level with financial risk. A plan that covers the Part B deductible might be important to you if you anticipate regular doctor’s appointments.

Remember, to purchase a Medigap policy, you first need to be enrolled in Original Medicare (Part A and Part B). These supplement plans are designed to fill the gaps in that coverage, so understanding your current and future health needs is the best place to start your search. This self-assessment will give you a clear picture of what level of coverage you’ll feel most comfortable with.

Compare Plan Benefits and Costs

One of the most helpful things to know about Medigap is that the plans are standardized. This means that a Plan G from one company offers the exact same basic benefits as a Plan G from any other company. This makes it much easier to compare your options. Once you’ve decided which plan letter (like F, G, or N) fits your needs, your main focus can shift to the cost.

The price for the same plan can vary significantly between insurance companies. It’s also important to remember that your premium can go up over time. In fact, some companies are known for offering low introductory rates only to implement large rate increases down the road. Comparing quotes from several different insurers is the best way to ensure you’re getting a fair price now and for years to come.

Research Insurance Company Reputations

While cost is a major factor, it shouldn’t be the only one. The company behind the plan matters. A low monthly premium isn’t worth much if the company provides poor customer service or has a history of unstable pricing. Before you sign up, take some time to research the reputation of the insurance companies you’re considering. Look at their financial strength ratings from agencies like A.M. Best and read reviews from current policyholders.

Working with a stable, reputable company helps you avoid issues and ensures you’re being treated fairly. Well-established insurers can be a good place to start when you want to learn about specific Medigap plans and their costs. A little research upfront can provide a lot of peace of mind later.

Medigap vs. Medicare Advantage: What’s the Difference?

When you first become eligible for Medicare, you face a big decision: how do you want to receive your benefits? You can stick with Original Medicare and add a Medigap plan, or you can choose a Medicare Advantage plan instead. These are two very different paths, and understanding the distinction is the key to picking the right coverage for your needs.

Think of it this way: a Medigap plan works with Original Medicare. It’s an extra policy you buy from a private company that helps pay for the costs that Original Medicare doesn’t cover. A Medicare Advantage plan, on the other hand, is a way to get your Medicare benefits from a private company. It replaces Original Medicare and bundles your hospital, medical, and often prescription drug coverage into one plan. Let’s break down what that means for your coverage, your choice of doctors, and your budget.

Key Differences in Coverage

The main difference between these two options comes down to how they are structured. Medigap plans are designed to fill the “gaps” in Original Medicare, helping to cover your deductibles, copayments, and coinsurance. The coverage is standardized, meaning a Plan G from one company has the same basic benefits as a Plan G from another. However, Medigap plans don’t typically include extra perks like routine dental, vision, or hearing aids, and you’ll need a separate Part D plan for prescription drugs.

Medicare Advantage (also known as Part C) is an all-in-one alternative. These plans must provide at least the same level of coverage as Original Medicare, but they often include additional benefits to attract members. It’s common to find Medicare Advantage plans that cover prescription drugs, dental, vision, and even gym memberships. These bundled coverage options can be convenient, but they come with different rules and costs.

Access to Doctors and Hospitals

Your freedom to choose your healthcare providers is a major point of contrast. With Original Medicare and a Medigap plan, you can see any doctor or go to any hospital in the U.S. as long as they accept Medicare. You don’t need to worry about staying in a network, and you generally don’t need a referral to see a specialist. This flexibility is one of the biggest draws for people who choose Medigap.

Medicare Advantage plans usually operate with provider networks, similar to an HMO or PPO. This means you’ll need to use doctors, hospitals, and specialists that are part of the plan’s network to keep your costs down. If you see a provider outside the network, your services may not be covered at all, or you could face much higher out-of-pocket costs. Many plans also require you to get a referral from your primary care physician before seeing a specialist.

Comparing Your Total Costs

The cost structure for Medigap and Medicare Advantage is fundamentally different. If you choose a Medigap plan, you will pay your monthly Part B premium to the government, plus a separate monthly premium to the private insurance company for your Medigap policy. While your fixed monthly costs are higher, your out-of-pocket expenses for medical care are often minimal or even zero. This makes your healthcare spending highly predictable from month to month.

Medicare Advantage plans often feature low or even $0 monthly premiums (though you must still pay your Part B premium). The trade-off is that you will pay copayments, coinsurance, and deductibles when you access care. Your costs will vary depending on how many medical services you use. While these plans have an annual out-of-pocket maximum to protect you from catastrophic costs, your monthly budget can be less predictable than with a Medigap plan.

Avoid These Common Medigap Enrollment Mistakes

Choosing a Medigap plan is a significant step in managing your health care costs, but it’s easy to make a misstep along the way. A few common errors can lead to paying more than you need to or even missing your chance to get the coverage you want. By understanding these potential pitfalls ahead of time, you can make a more informed decision for your future. Let’s look at the most frequent mistakes people make when enrolling in a Medicare Supplement plan and how you can sidestep them.

Missing Your Initial Enrollment Window

Think of your Medigap Open Enrollment Period as a golden ticket. This is your one-time, six-month window to buy any Medigap policy sold in your state, regardless of your health history. It starts on the first day of the month you are both 65 or older and enrolled in Medicare Part B. During this period, an insurance company cannot deny you coverage or charge you a higher premium because of pre-existing conditions. Missing this window is one of the biggest mistakes you can make. If you try to apply for a plan later, insurers can generally use medical underwriting, which means they could deny your application or charge you significantly more based on your health.

Choosing a Plan Based on Price Alone

While your budget is certainly a major factor, picking a Medigap plan based only on the lowest monthly premium can be a costly mistake. Medigap plans are standardized by the federal government, which means a Plan G from one company has the exact same benefits as a Plan G from another. The main differences are the price and the company behind the plan. It’s important to also consider an insurer’s reputation for customer service and their history of rate increases. A plan with a low introductory premium might see steep price hikes down the road. Your goal should be to find the best long-term value, not just the cheapest price today.

Overlooking Your Guaranteed Issue Rights

Many people don’t realize they have special protections called guaranteed issue rights that allow them to buy a Medigap policy without answering health questions. Your Medigap Open Enrollment Period is the most common time you have these rights. However, they can also apply in other specific situations, like if you lose your employer health coverage after turning 65. Understanding when these rights apply is crucial. If you fail to use them when you’re eligible, you might miss your best opportunity to secure a Medigap plan, especially if you have health issues that could cause an insurer to deny your application later.

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Frequently Asked Questions

If all plans with the same letter are identical, why are the prices so different? This is one of the most important things to understand about Medigap. While the government standardizes the benefits of each plan letter, it doesn’t regulate the price. That means private insurance companies are free to charge different monthly premiums for the exact same coverage. One company might set a lower price to attract new customers, while another might have higher overhead costs. This is why it’s so important to compare quotes for the specific plan you want from several different companies to find the best value.

I missed my Medigap Open Enrollment Period. Is it too late to get a plan? No, it’s not necessarily too late, but your options change. You can apply for a Medigap plan at any time, but if you’re outside your initial six-month window, insurance companies can generally require you to answer health questions. This process is called medical underwriting. Based on your health history, they could charge you a higher premium or even deny your application. There are some special circumstances that give you another chance to enroll without underwriting, but for most people, that initial window is the easiest and most secure time to sign up.

Do I also need to buy a separate plan for my prescriptions? Yes, in almost all cases you will. Medigap plans are designed to work with Original Medicare Parts A and B and do not include coverage for prescription drugs you take at home. To get help with medication costs, you will need to enroll in a standalone Medicare Part D Prescription Drug Plan. It’s a good idea to sign up for a Part D plan when you first become eligible to avoid a life-long late enrollment penalty.

Can I switch from my Medicare Advantage plan to a Medigap plan? Switching is possible, but the rules can be tricky. You can generally only leave your Medicare Advantage plan during specific times of the year, like the Annual Election Period in the fall. More importantly, when you apply for a Medigap plan after having been in a Medicare Advantage plan, you will likely have to go through medical underwriting unless you qualify for a special enrollment period. This means an insurance company can look at your health history to decide whether to accept your application and how much to charge you.

Will my Medigap plan work if I travel to another state? Absolutely. One of the biggest benefits of having a Medigap plan is the freedom it gives you. Since it supplements Original Medicare, you can see any doctor or visit any hospital in the United States as long as they accept Medicare. You are not restricted to a local network of providers, which gives you great flexibility and peace of mind, whether you’re traveling, visiting family, or a snowbird spending winters in a warmer state.

About the Author

Karl Bruns-Kyler is a licensed independent Medicare insurance broker with over 20 years of experience helping clients make confident, informed healthcare decisions. Based in Highlands Ranch, Colorado, Karl works with Medicare recipients across more than 30 states, offering personalized guidance to help them avoid costly mistakes, find the right coverage, and maximize their benefits. Connect on LinkedIn