There is no single "best" Medicare supplement — the right plan depends on what you need to pay out of pocket

Medicare supplement insurance (also called Medigap) fills gaps in what Original Medicare covers. The "best" plan is not the highest-rated one — it is the one that matches your health needs and budget. A plan that works well for someone with frequent doctor visits may cost too much for someone who is generally healthy. Rating systems rank plans by customer service and claims handling, not by whether the plan itself is right for you.

All Medicare supplement plans are standardized by federal law, which means Plan G from one insurance company covers exactly the same things as Plan G from another. The differences are in price, customer service, and whether the company is straightforward to work with when you file a claim. This guide explains how to find plans in your area, what ratings actually measure, and how to pick one that fits your situation.

Key Takeaways

  • All Medicare supplement plans with the same letter (Plan G, Plan N, Plan F) cover identical benefits no matter which company sells them, so you are comparing price and customer service, not coverage.
  • J.D. Power, Consumer Reports, and the National Association of Insurance Commissioners (NAIC) rate plans on claims handling and customer service, not on whether the plan is medically right for you.
  • The lowest-priced plan in your area may not have the best ratings, and the highest-rated plan may not be the cheapest — you have to decide what matters more to your budget.
  • Plans are priced differently by age and location, so comparing rates online requires entering your zip code and birth date to see actual prices in your area.
  • You can switch plans once a year during the annual enrollment period, so choosing a plan now does not lock you in forever.

How Medicare supplement plans are standardized and why that matters

The federal government sets what each lettered plan must cover. Plan G covers the same hospital deductible, coinsurance, and copayments whether you buy it from Aetna, United Healthcare, or a regional carrier. You cannot find a "better" Plan G — only a cheaper one or one with faster claims processing.

This standardization means you should never choose a plan based on the company's marketing. Instead, compare the same letter plan across different companies in your area. If Plan G costs $120 a month from one company and $145 from another, and both have similar customer service ratings, the cheaper one is the better financial choice.

The ten standardized plans available are A, B, D, G, K, L, M, and N (Plan C and F are closed to new people turning 65 after 2020). Each covers a different combination of Medicare's gaps. Plan G is the most popular because it covers most of what Original Medicare does not, except for the Part B deductible. Plan N is cheaper but requires you to pay small copayments at the doctor's office.

What rating systems actually measure

J.D. Power ranks insurance companies on customer satisfaction, including how straightforward it is to reach someone, how quickly they answer questions, and whether claims are paid correctly. Consumer Reports surveys people about their experiences with claims and customer service. The National Association of Insurance Commissioners (NAIC) publishes complaint data — how many complaints each company receives per 1,000 customers.

These ratings do not measure whether a plan is medically right for you. They measure whether the company is straightforward to work with. A highly rated company might still sell a plan that does not match your health needs. A lower-rated company might still offer the cheapest price in your zip code.

When you look up ratings, check the year they were published. Insurance company performance changes, and a company that ranked well two years ago may have different customer service now. J.D. Power publishes new rankings each year, usually in the fall.

How to compare plans in your actual area

Medicare supplement prices vary by zip code and by your age when you enroll. A plan that costs $100 a month in one county may cost $150 in the next county. The only way to see real prices is to enter your zip code and birth date into a comparison tool.

Medicare.gov has an official plan finder tool. Enter your zip code, and it shows all plans available in your area, their monthly premiums, and which companies sell them. You can also call 1-800-MEDICARE and ask for a list of plans and prices in your area — a representative will read them to you over the phone.

When you compare, write down the monthly premium for the same plan letter from at least three companies. Then look up each company's customer service rating using J.D. Power or NAIC complaint data. If two companies have similar ratings but different prices, the cheaper one is usually the better choice. If one company has notably better ratings but costs $20 more per month, decide whether that extra service is worth the cost to you.

The difference between enrollment age and plan pricing

Medicare supplement companies can charge different prices based on your age when you first enroll. Some use "issue age" pricing, which means your rate is locked to your age at enrollment and goes up slowly each year. Others use "attained age" pricing, which means your rate goes up faster as you get older. A few use "no age" pricing, where everyone pays the same regardless of age.

This matters over time. With issue age pricing, a 65-year-old might pay $100 a month and still pay around $110 at age 75. With attained age pricing, that same person might pay $100 at 65 but $160 at 75. Over ten years, the difference adds up.

When you compare plans, ask the company which pricing method they use. Some companies list it on their website; others require a phone call. If you plan to keep the same plan for many years, issue age pricing is usually cheaper in the long run, even if the starting price is higher.

When to switch plans and what it costs

You can change Medicare supplement plans once a year during the annual enrollment period, which runs from October 15 to December 7. The new plan takes effect January 1. You can also switch if you move to a different state or if your current company stops selling that plan in your area.

Switching plans does not cost anything — there is no penalty or waiting period. However, if you have a pre-existing condition, some companies may deny you or charge more when you switch. This protection is strongest if you switch within 63 days of losing your current coverage. After that window, companies can underwrite you (review your health history) and may refuse to sell you a plan.

Because of this, do not wait until you are very sick to switch. If you think you might want a different plan, switch during the annual enrollment period while you still have protection. Once you are enrolled in a new plan, you cannot be denied or charged more based on health.

Red flags when choosing a company

Check the NAIC complaint database before you enroll. It shows how many complaints each company received in the past year and what the complaints were about. A company with 50 complaints per 1,000 customers is a red flag. A company with 5 complaints per 1,000 is typical.

Look for patterns in complaints. If most complaints are about claims not being paid, that is a serious problem. If most are about billing or customer service, that is annoying but less critical. You can read summaries of complaints on the NAIC website by state and company.

Also check whether the company is licensed to sell in your state. Some companies sell in most states but not all. Medicare.gov's plan finder only shows plans available where you live, so this is usually not a problem, but it is worth confirming if you are comparing plans online.

Questions to ask before you enroll

Call the company before you sign up and ask: What is your pricing method — issue age, attained age, or no age? How many complaints did you receive last year? Can I reach customer service by phone 24 hours a day? How long does it usually take to process a claim? Do you have a mobile app or online portal to check claim status?

Write down the answers. If a company is hard to reach or vague about pricing, that is a sign they may be difficult to work with later. If they answer clearly and quickly, that is a good sign.

You should also ask whether the plan covers your current doctors and hospitals. Medicare supplement plans do not have networks — any doctor who accepts Medicare accepts your plan. But it is worth confirming that your preferred providers are in your area and still accepting new patients.

Frequently Asked Questions

Is Plan G or Plan N better?

Plan G costs more but covers more. Plan N costs less but requires you to pay small copayments at the doctor ($20 per visit) and at urgent care ($50). If you see doctors frequently, Plan G may cost less overall. If you rarely see doctors, Plan N saves money. Compare the total monthly cost plus what you would pay out of pocket based on your health.

Can I switch plans if I am unhappy with my company?

Yes, during the annual enrollment period (October 15 to December 7) you can switch to a different company or a different plan letter. The new plan starts January 1. If you switch within 63 days of losing coverage, companies cannot deny you or charge more based on health. After that, they can review your health history.

Why do prices vary so much between companies?

Companies set their own prices based on their costs, profit margins, and how many customers they have in your area. A large national company might charge less because they have more customers to spread costs across. A smaller regional company might charge more or less depending on their business strategy. This is why comparing prices across companies is essential.

Do I need the highest-rated plan?

Not necessarily. A highly rated company is easier to work with, but all plans with the same letter cover the same benefits. If a lower-rated company charges $30 less per month and has acceptable complaint levels, the savings may be worth it. If a company has very high complaints, the extra cost of a better-rated company is usually worth paying.

What happens if my company stops selling my plan?

If your company discontinues your plan, they must notify you at least 30 days in advance. You can then switch to a different plan or a different company without penalty, even outside the annual enrollment period. You have a may provide issue period (usually 63 days) to switch without health underwriting.