Medicare Supplement Carrier Ratings 2026 — A.M. Best + NAIC Complaint Index

Carrier	A.M. Best ↓	NAIC Complaint Index	Market Share	States	Plans
UnitedHealthcare Insurance Co (AARP) Parent: UnitedHealth Group · NAIC #: 79413 Largest U.S. Medigap carrier by market share. AARP-branded; co-branded contract since 1997.	A Excellent	0.30 – 0.90	~36.0%	50	G, N, F (closed), HD-G, K, L
Mutual of Omaha Insurance Company Parent: Mutual of Omaha · NAIC #: 71412 Higher A.M. Best than UHC. Long-standing Medigap underwriter; household discount up to 12%.	A+ Superior	0.20 – 0.65	~9.5%	49	G, N, HD-G, A, F (closed)
Aetna Health and Life Insurance Co Parent: CVS Health · NAIC #: 78700 Large carrier with strong rates in select states; full plan-letter selection.	A Excellent	0.25 – 0.80	~6.5%	49	G, N, F (closed), HD-G, A, B
Cigna Health and Life Insurance Co Parent: Cigna Group · NAIC #: 67369 Competitive on Plan G nationally; smaller plan-letter selection.	A Excellent	0.25 – 0.85	~5.0%	47	G, N, F (closed), HD-G
Humana Insurance Company Parent: Humana Inc · NAIC #: 73288 Primary focus is Medicare Advantage; Medigap is secondary line.	A- Excellent	0.40 – 1.10	~4.5%	48	G, N, F (closed)
Manhattan Life Insurance Co Parent: Manhattan Life Group · NAIC #: 65870 Niche Medigap underwriter; competitive rates with attained-age structure.	A- Excellent	0.20 – 0.75	~1.8%	45	G, N, HD-G, F (closed)
Bankers Fidelity Life Insurance Co Parent: Atlantic American Corp · NAIC #: 61239 Mid-size Medigap-focused carrier; community-rated structure in some states.	A- Excellent	0.25 – 0.95	~1.2%	42	G, N, F (closed), A
Continental General Insurance Co Parent: HC2 Holdings · NAIC #: 71404 Lower A.M. Best than top-tier carriers; verify state-specific complaint index before selecting.	B+ Good	0.35 – 1.20	~0.9%	39	G, N, A, B, F (closed)
USAA Life Insurance Company Parent: USAA · NAIC #: 69663 Highest A.M. Best rating in the directory. Eligibility limited to military/family. Excellent complaint index.	A++ Superior	0.10 – 0.40	~0.8%	50	G, N, F (closed)
Globe Life and Accident Insurance Parent: Globe Life Inc · NAIC #: 91472 Multi-line carrier with Medigap line; check state-specific rates.	A Excellent	0.30 – 1.00	~0.7%	49	G, N, F (closed)
Anthem (BCBS subsidiaries) Parent: Elevance Health · NAIC #: various BCBS-branded Medigap is sold via Anthem in states where they operate. Check your specific state's Anthem entity.	A Excellent	0.35 – 1.10	~4.2%	14	Varies by state — typically G, N, F
Western United Life Assurance Co Parent: Manhattan Life Group · NAIC #: 85189 Manhattan Life subsidiary; tight focus on Medigap with attained-age pricing.	A- Excellent	0.20 – 0.70	~0.5%	33	G, N, HD-G
Liberty Bankers Life Insurance Co Parent: Liberty Bankers Insurance Group · NAIC #: 68543 Mid-tier financial strength; verify NAIC complaint index for your state before selecting.	B++ Good	0.40 – 1.30	~0.4%	38	G, N, F (closed), A
Sentinel Security Life Insurance Parent: A-Cap Holdings · NAIC #: 68829 Smaller carrier; A.M. Best rating below top tier. Higher complaint index range — investigate carefully.	B++ Good	0.45 – 1.40	~0.3%	30	G, N, F (closed)
New Era Life Insurance Co Parent: New Era Life Group · NAIC #: 78743 Smaller niche carrier; verify state-specific rates and complaints before selecting.	B++ Good	0.50 – 1.50	~0.2%	26	G, N, F (closed), A

📋 Methodology

Data sources (all primary, public):

A.M. Best ratings: Public A.M. Best directory at ambest.com/ratings-services. Ratings reflect financial strength, NOT customer service or premium competitiveness.
NAIC complaint index: National Association of Insurance Commissioners' Consumer Information Source at eapps.naic.gov/cis. We show the range observed in 2022-2024 reporting because complaint indices vary by state and year. For your state's current value, look up the carrier directly.
Market share: Approximate U.S. Medicare Supplement enrollment share, sourced from CMS Medicare Enrollment Dashboard data and AHIP annual Medigap enrollment reports.
Plan letter availability: Compiled from carrier rate filings with state insurance departments and carrier consumer materials. Plan F is shown as "(closed)" because federal law closed Plan F to new Medicare-eligible beneficiaries in 2020 — current Plan F policies remain in force, but new enrollment is restricted to those eligible for Medicare before Jan 1, 2020.

What this lookup is good for: shortlisting carriers based on financial strength and complaint history. Carriers above the threshold you set in the filter are reasonable shortlisting candidates.

What this lookup is NOT good for: picking a final carrier without comparing rates, rate-increase history, plan letter availability in your state, and your specific underwriting situation. Two carriers with identical A.M. Best ratings can charge $80/mo apart for the same person at the same age — premium comparison is a separate exercise.

Update cadence: A.M. Best ratings refresh quarterly to annually per carrier; we audit this table semi-annually (June and December) and within 30 days of any major Medigap-carrier rating action. NAIC complaint data publishes annually each spring; we refresh the index ranges within 60 days of publication.

How to use this table to shortlist a Medigap carrier

A four-step process that takes <15 minutes.

Step 1 — Filter to A or higher A.M. Best

The default filter is "A or higher" because Medigap policies are 20+ year financial commitments. A-rated carriers have negligible insolvency risk historically — even smaller A-rated carriers are protected by state guaranty funds. Below A- (B++/B+) is acceptable for shorter horizons but adds risk you should consciously accept.

Step 2 — Filter complaint index to ≤ 1.0

1.0 = industry average. Below 1.0 means the carrier receives fewer complaints than its market share would predict — a positive signal for claims handling, billing accuracy, and customer service. Above 1.0 is a yellow flag worth investigating before selecting.

Step 3 — Verify the carrier sells your plan letter in your state

Plan G is offered by virtually all carriers. Plan N is also widely available. Plan HD-G (high-deductible G) is offered by fewer carriers — if you want HD-G, your shortlist narrows. Plan F is closed to new Medicare-eligible beneficiaries (those who became eligible after Jan 1, 2020) — federal law, not carrier choice.

Step 4 — Get carrier-specific quotes

This table eliminates carriers; it does NOT pick a winner. Two carriers with identical A.M. Best ratings can charge $80/mo apart for the same 65-year-old in the same ZIP. A licensed independent agent with access to every carrier in your state will get you the actual numbers — at no cost (agents are paid by carriers; the monthly premium is identical whether you enroll through an agent or directly with the carrier).

Frequently Asked Questions

What is the NAIC complaint index?+

The NAIC complaint index is a ratio published by the National Association of Insurance Commissioners that compares a carrier's number of consumer complaints to its share of the market. A complaint index of 1.0 = exactly average. Below 1.0 = the carrier has fewer complaints than its market share would predict (good). Above 1.0 = more complaints than market share predicts (concerning). The index is calculated separately for each state and product line and updated annually. Look up live state-specific values at NAIC's Consumer Information Source: eapps.naic.gov/cis.

What is an A.M. Best rating?+

A.M. Best is the leading independent rating agency for the insurance industry. Their financial strength rating measures a carrier's ability to meet ongoing obligations to policyholders. Scale: A++ (Superior), A+ (Superior), A (Excellent), A- (Excellent), B++ (Good), B+ (Good), B (Fair), B- (Fair), C++/C+/C/C- (Marginal), D (Poor). For Medicare Supplement, prefer A or higher — these carriers have very low historical insolvency rates. Below B+ warrants extra scrutiny on complaint history and state guaranty fund coverage.

Which Medicare Supplement carrier has the highest rating?+

USAA Life Insurance Company holds the highest A.M. Best rating (A++ Superior) among major Medigap carriers — but eligibility is limited to military members and their families. Mutual of Omaha Insurance Company holds A+ (Superior) with no eligibility restriction and is the highest-rated broadly-available Medigap carrier. UnitedHealthcare/AARP holds A (Excellent) and is the largest by market share.

Should I pick the carrier with the lowest complaint index?+

Complaint index is one signal, not the only one. Weigh it against (1) A.M. Best financial strength, (2) Premium rate in your specific ZIP and age, (3) Rate-increase history, (4) Plan letter availability, (5) Customer service ease for claims and disputes. The right carrier balances all five — not just one metric.

Why are the complaint indices shown as ranges instead of single numbers?+

NAIC complaint indices vary by state and reporting year. The same carrier can have a complaint index of 0.30 in one state and 0.85 in another — driven by local regulatory environment, agent network quality, and claims-handling practices. We show the range observed across NAIC reporting (2022-2024) to give an honest band. For your specific state's current index, look up the carrier on NAIC Consumer Information Source: eapps.naic.gov/cis (free, public, official).

What is the Medigap insolvency / state guaranty fund safety net?+

Every state operates a guaranty association that protects policyholders if an insurance carrier becomes insolvent. For Medicare Supplement (and life/health insurance generally), state guaranty funds typically cover up to $300,000 in claims per insured per company (varies by state). Practically: pairing a B+ or higher A.M. Best rating with state guaranty fund coverage means insolvency risk for Medigap policyholders is extremely low historically.

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Medicare Supplement Carrier Ratings — A.M. Best, NAIC Complaint Index, and Market Position.

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