AM Best Affirms Credit Ratings of SUNZ Insurance Company, a Key Carrier Partner in the GMS Insurance Ecosystem 

RICHFIELD, OH, May 4, 2026 — Group Management Services (GMS) works closely with insurance partners that demonstrate long‑term financial strength, stability, and disciplined risk management. We’re pleased to share that AM Best has reaffirmed the Financial Strength Rating of A‑ (Excellent) and Long‑Term Issuer Credit Rating of “A- (Excellent)” for SUNZ Insurance Company, with a stable outlook. 

AM Best is a globally recognized, independent credit rating agency focused exclusively on the insurance industry. Its ratings assess an insurer’s balance sheet strength, operating performance, business profile, and enterprise risk management. An “A‑ (Excellent)” rating signals strong financial performance and the ability to meet ongoing policyholder obligations. 

SUNZ Insurance is a specialized workers’ compensation carrier with deep experience supporting professional employer organizations (PEOs), staffing firms, transportation companies, and large employers across the United States. According to AM Best, the affirmed ratings reflect SUNZ’s balance sheet strength, operating performance, business profile, and enterprise risk management practices.  

Why This Matters for GMS Clients 

At GMS, we are intentional about the insurance relationships we establish and maintain. Carrier selection is not just about access to coverage, it’s about long‑term reliability, financial discipline, and alignment with our risk management philosophy. 

Strong third‑party validation from organizations like AM Best reinforces that GMS partners with insurers that take a disciplined approach to underwriting, capitalization, and risk oversight. For businesses evaluating a PEO relationship, this level of rigor matters, especially for organizations with risk‑averse leadership teams or complex workers’ compensation exposures. 

Built on Disciplined Decisions and Trusted Relationships 

Our role as a PEO extends beyond administration and compliance. GMS is focused on building a resilient insurance ecosystem designed to support clients through changing market conditions, regulatory environments, and economic cycles. That means working only with carriers that meet high standards for financial strength and operational integrity. 

SUNZ’s continued “Excellent” rating reinforces the importance of careful vetting, strong partnerships, and long‑term thinking, principles that guide how GMS serves and protects its clients every day. 

To read the full announcement from SUNZ Insurance, visit: AM Best Affirms Credit Ratings of SUNZ Insurance Company