AM Specialty Insurance Group has named Matt Mosher to its board of directors, bringing a former rating agency chief executive into the specialty carrier's governance structure as the US excess and surplus market enters a more competitive phase.
Mosher arrives at the AM Specialty board after nearly three decades at AM Best, where he most recently served as president and chief executive officer. His earlier posts at the rating agency included executive vice president and chief operating officer, chief rating officer, and CEO of AM Best America Latina.
Across those positions, he oversaw global rating operations spanning multiple international markets. Mosher is known within the sector for his work on rating methodologies and credit analysis frameworks.
He played a central part in shaping AM Best's Capital Adequacy Ratio, or BCAR, model, which insurers and analysts rely on to gauge financial strength, and contributed to integrating innovation-based assessments into the agency's rating process.
Mosher retired as president and CEO of AM Best Rating Services at the end of 2024. He has since taken on several industry roles, including a board seat at Pharmacists Mutual in July 2025 and a strategic advisor position at Stonybrook Capital & Risk Management in May 2025. He is a graduate of Lehigh University with a bachelor of science in statistics.
Shevawn Barder, group chief executive officer of AM Specialty Insurance Group, said the appointment adds meaningful depth to oversight. "Matt's appointment to our Board represents a significant addition to the Group," Barder said, noting that his grasp of carrier performance and disciplined underwriting will support long-term strategy.
Headquartered in Dallas and operating under parent AM Holding Co, AM Specialty comprises an Arizona-domiciled E&S carrier rated A- (Excellent) by AM Best, a UK wholesale arm, reinsurance syndicate AM RE, claims manager AM Star Claims, and UK-based MGA Pinpoint, which it acquired in June 2024.
Unlike fronting carriers, its US E&S entity retains meaningful risk on the programs it underwrites.
The Mosher appointment follows a wider leadership refresh. The group promoted Dominick Tassone Jr. to CEO of its US subsidiary effective January 2026 and elevated Olivia Barder to group chief operating officer in September 2025.
The timing is notable. S&P Global Market Intelligence data shows the US E&S market crossed $105 billion in direct premiums written in 2025, surpassing the $100 billion threshold for the first time. Growth slowed to 7.8%, the first single-digit rate since 2017 and down from 13.4% the prior year.
AM Best revised its outlook for the US E&S segment from positive to stable in November 2025, citing moderating premium growth and early rate softening.
The agency's Edin Imsirovic said early rate softening in classes such as commercial property, slowing premium growth and more-selective capacity deployment now warrant a stable outlook – a backdrop where board-level rating expertise carries added weight.
