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Top 10 Best Medicare Supplement Companies in 2026
UnitedHealthcare, sold through AARP, is the largest Medicare Supplement company in the United States by a wide margin, with 4.27 million members and 31 percent of the market at the end of 2025, according to Mark Farrah Associates. Mutual of Omaha ranks second with 1.3 million members and 9.4 percent. The ten largest companies together cover 71 percent of the market, over 9.8 million members. Because every Plan G policy covers the same benefits by law, the company you pick matters for price, price stability, and service, not for what the plan covers.
Medicare Supplement insurance, also called Medigap, fills the gaps Original Medicare leaves: the Part A and Part B deductibles, coinsurance, and copayments. Plans are standardized by letter, so Plan G from UnitedHealthcare pays the same benefits as Plan G from Mutual of Omaha. What differs is the monthly premium, how fast it rises, the discounts, and how easy the company is to deal with. This guide ranks the ten companies that matter most in 2026, using enrollment data from Mark Farrah Associates and published Plan G rate comparisons.
Who are the 10 largest Medicare Supplement companies?
The ranking below starts with the enrollment leaders reported by Mark Farrah Associates for December 31, 2025, then rounds out the top ten with the national carriers buyers most often compare. Enrollment figures are stated where Mark Farrah Associates published them; where a company sits outside the published top ranks, the guide says so plainly instead of inventing a rank.
| Company | Members (end of 2025) | Market share | What it is known for |
|---|---|---|---|
| 1. UnitedHealthcare (AARP) | 4.27 million | 31% | Largest pool, sold in all 50 states, household discount |
| 2. Mutual of Omaha | 1.3 million | 9.4% | Long rate stability, household discount, A+ rating |
| 3. HCSC (Blue Cross Blue Shield) | Over 1.2 million | Top 3 | Blue Cross licensee, grew by acquiring Cigna’s Medicare business |
| 4. CVS Health (Aetna) | 953,000 | Top 4 | Aetna brand, CVS pharmacy integration |
| 5. Elevance Health (Anthem BCBS) | About 649,000 (2024) | Top 5 in 2024 | Anthem Blue Cross Blue Shield licensee states |
| 6. Cigna | National carrier | Top 10 | Competitive introductory Plan G rates, household discount |
| 7. Humana | National carrier | Top 10 | Part D bundling, large Medicare brand |
| 8. State Farm | National carrier | Top 10 | Local agent network, service reputation |
| 9. Globe Life | National carrier | Top 10 | Direct-to-consumer sales, low introductory rates |
| 10. Manhattan Life | Regional strength | Top 10 | Competitive rates in Northeast and Southeast states |
Two facts in this table deserve attention. First, the top ten companies cover 71 percent of the market, so most buyers end up with one of these names whether they shop widely or not. Second, UnitedHealthcare alone is bigger than the next three companies combined. A pool that large tends to spread risk and soften rate swings, which is part of why AARP plans stay competitive even when they are not the cheapest quote in a given zip code.
What does Plan G cost at each company?
Plan G is the most popular Medigap plan, with over 5.7 million members in 2024, and it is the fairest way to compare companies because the benefits are identical. The table below shows average monthly Plan G rates for a 65-year-old woman who does not smoke, from ValuePenguin’s published carrier comparison. Your rate will differ by state, age, gender, tobacco use, and rating method.
| Company | Average Plan G rate, 65-year-old woman |
|---|---|
| Cigna | $166 a month |
| AARP (UnitedHealthcare) | $177 a month |
| USAA | $186 a month |
| Blue Cross Blue Shield | $189 a month |
| Humana | $195 a month |
| Aetna (CVS) | $198 a month |
| Mutual of Omaha | $207 a month |
The spread here is $41 a month, about $492 a year, between the cheapest and priciest large carrier in this comparison. That gap is real money, and it is also smaller than the gap between states: Medicare.gov listings from October 2026 put AARP Plan G for a woman at $212.11 a month in Dallas, $181.30 in Columbus, and $201.89 in Phoenix, with a household discount cutting those to $177.01, $160.26, and $178.49. Always compare quotes in your own zip code, because a company that is cheapest nationally can be mid-priced in your state.
How does each company compare in detail?
UnitedHealthcare through AARP is the default choice for buyers who value scale and stability. It sells in every state, its NAIC complaint index ran 0.54 to 0.73 from 2023 to 2025, below the 1.00 expected for a company its size, and its AM Best rating is A (Excellent), cut from A+ in August 2025. The catch is pricing method: AARP plans use community rating with an enrollment discount that fades after age 68, so the early-years discount disappears over time. AARP membership costs about $16 a year and is required.
Mutual of Omaha is the stability pick. Its Plan G averages $207 a month for a 65-year-old woman in the ValuePenguin comparison, the highest of the large carriers shown, yet it becomes relatively cheaper by age 85, when its rate averages $243 against $272 for Humana and $262 for Blue Cross Blue Shield. That pattern is the point: Mutual of Omaha tends to start higher and rise more slowly. Buyers who plan to hold the policy for decades often come out ahead with it.
HCSC, the Blue Cross Blue Shield licensee behind several state plans, jumped to third place in 2025 after acquiring Cigna’s Medicare business, adding about 646,000 members. Blue Cross plans vary by state because each licensee sets its own rates, so a Blue plan that is cheap in Illinois can be expensive in Texas. Check the licensee in your state, not the national brand.
CVS Health, selling as Aetna, ranks fourth with 953,000 members, though it lost about 96,600 members year over year in 2025, the largest decline among the leaders. Its Plan G averages $198 a month in the comparison above. The CVS connection helps buyers who want their drug plan and supplement under one roof, and its digital tools are strong.
Elevance Health, the Anthem Blue Cross Blue Shield parent, ranked fourth in 2024 with almost 649,000 members. Cigna, now largely folded into HCSC’s book, still appears in rate comparisons with the cheapest average Plan G quote at $166 a month, a reminder that legacy Cigna policies remain in force and that introductory pricing can be aggressive. Humana averages $195 a month and pairs well with a Humana Part D plan. State Farm sells through local agents, which suits buyers who want a person, not a portal. Globe Life and Manhattan Life round out the list as price-aggressive options worth quoting, especially in states where the big carriers run hot.
Why does the rating method matter more than the first-year price?
Companies price Medigap three ways. Community-rated plans charge everyone the same base premium regardless of age, as AARP does. Issue-age-rated plans lock the premium to your age at purchase, so a policy bought at 65 stays cheaper than one bought at 75. Attained-age-rated plans rise as you age, so they look cheap at 65 and climb steadily. A $135 attained-age quote at 65 that reaches $210 by 75 costs more over a decade than a $160 issue-age quote that barely moves. Ask every carrier for its rating method and its rate increase history over the last five years before you sign.
What should you check before you buy?
Check four items. First, the plan letter: Plan G covers everything except the Part B deductible, and it is the best fit for most new enrollees, while Plan N trades lower premiums for copays on office and emergency visits. Second, the rating method, as above. Third, the household discount: most large carriers cut 5 to 12 percent when two people in a household enroll. Fourth, the company’s complaint record with your state insurance department and its AM Best financial strength rating. A cheap premium from a carrier with a weak rating or a heavy complaint load is a bad trade for a policy you may hold for 20 years.
Key takeaways
- UnitedHealthcare (AARP) leads with 4.27 million members and 31 percent of the market; Mutual of Omaha is second at 1.3 million.
- Plan G benefits are identical across companies, so compare price, rating method, and rate history, not coverage.
- Average Plan G for a 65-year-old woman runs $166 to $207 a month across the large carriers in published comparisons.
- Mutual of Omaha starts higher and rises more slowly; Cigna and AARP quote lower at 65.
- Always get quotes in your own zip code, because state variation beats national averages.
Related reading on this site: our Medigap Plan G guide, Medigap cost comparison chart, top 5 Medicare Supplement plans, Plan G pros and cons, and Plan F vs Plan G. Enrollment figures come from Mark Farrah Associates; Plan G rate averages come from ValuePenguin.
Frequently asked questions
What is the best Medicare Supplement company in 2026?
UnitedHealthcare through AARP is the largest and most widely available, with 4.27 million members and a below-average complaint index. Mutual of Omaha is the best stability pick for buyers who plan to hold the policy for decades. The best company for you depends on your state’s rates and your rating method preference.
Is Plan G the same at every company?
Yes. Plan G benefits are standardized by federal law, so Plan G from any company covers the same Medicare gaps. Companies differ only in premium, rating method, discounts, service, and financial strength. Compare those, not the coverage letter.
How much does Plan G cost per month?
Published comparisons put average Plan G for a 65-year-old woman who does not smoke at $166 to $207 a month across large carriers. Actual rates vary by state: AARP Plan G for a woman runs about $181 a month in Columbus and $212 in Dallas before household discounts.
Do I need AARP membership to buy UnitedHealthcare Medigap?
Yes. UnitedHealthcare sells its Medicare Supplement plans through AARP, and membership costs about $16 a year. The membership requirement is nominal, and the household discount often outweighs it.
Can I switch Medicare Supplement companies later?
It depends on your state. Some states have birthday rules or guaranteed-issue windows that let you switch without underwriting. In most states, switching after your initial enrollment period requires health underwriting, and a carrier can decline you or charge more. That is why rate stability matters at purchase.
