Top 10 US Workers Compensation Insurers

Zurich North America writes $2.8B in workers' compensation premium, largely through loss-sensitive structures like large deductible and retrospective programs, which serve multinational corporations managing self-insured retentions above $500,000 per occurrence. It pairs these with an in-house risk engineering team that carries out on-site workplace safety assessments.

Nationwide began in 1926 as the Ohio Farm Bureau's own auto insurer and is still a Columbus-based mutual owned by its policyholders. That history is why it remains one of the few national carriers with real appetite for farm and agribusiness workers compensation, alongside a broad small-business book covering contractors, retail and light manufacturing.

Employers Holdings dominates the small-business workers comp arena as a pure-play specialist with $700 million in premiums. Listed on NASDAQ (EIG), it serves over 100,000 small employers in low-to-medium hazard industries, leveraging proprietary AI-powered underwriting for fast quotes and precise pricing. Unlike diversified insurers, its exclusive focus on small accounts ensures tailored risk assessment and competitive rates.

ICW Group leads with dividend plans that return premiums to employers with favorable loss experience. Writing $1.5 billion in WC premiums from San Diego, this Western US regional specialist also provides the SafetyFirst program at no extra cost, offering training resources to reduce claims. Its regional focus allows deeper local risk insights. For Western employers, ICW's blend of loss prevention support and premium rebates delivers tangible savings and safety improvements.

AmTrust Financial excels in specialty workers comp for staffing, healthcare, and retail sectors, with $2 billion in premiums. Taken private in 2018 for $2.7 billion after resolving prior reporting issues, it now operates a global platform spanning 8 countries. For staffing firms, AmTrust's international reach and niche expertise provide an alternative to ICW Group's regional dividend model.

CNA Financial is a Chicago-based commercial property and casualty insurer, majority owned by Loews Corporation, writing workers' compensation for mid-market and large accounts with complex exposures alongside its managed-care and risk-control services.

The Hartford, founded in Connecticut in 1810, is one of the largest US writers of workers' compensation insurance, with its strength concentrated in small and mid-sized commercial accounts placed through independent agents. It broadened its specialty lines with the $2.1 billion acquisition of Navigators Group in 2019.