Tom Doyle (pictured) will become CEO of Arthur J. Gallagher & Co.’s benefits and HR consulting division on January 1, 2027, succeeding Bill Ziebell, who is retiring after 26 years with the firm.
Doyle has served as division president and spent most of his career inside Gallagher’s regional operations before moving to the top role. Ziebell, who joined Gallagher in 2000 and built the benefits division into a global operation active across approximately 130 countries, will transition to chairman of the division. That structure keeps institutional knowledge in place while formally handing leadership to Doyle.
J. Patrick Gallagher, Jr., chairman and CEO, said Doyle’s “strong knowledge of the business” and “proven ability to bring teams and businesses together” positioned him well to lead the division forward. The language points to something specific: Doyle takes the job mid-integration.
Gallagher completed the $13.45 billion acquisition of AssuredPartners in August 2025, the largest deal in its history, which added employee benefits alongside commercial property/casualty and specialty as core lines. The combined entity reported total revenues of approximately $13.8 billion for 2025, with the brokerage segment, which includes employee benefits, targeting around 5.5% organic growth for 2026.
Lockton’s 2026 National Benefits Survey found that 54% of employers now rank cost reduction as their top benefits priority, up sharply from 38% in 2025, with attracting and retaining talent falling behind it. Clients pressing harder on cost give large platforms with analytical depth and carrier leverage a structural advantage over smaller independents. Gallagher’s expanded footprint, built through sustained acquisition activity that included Buck, AssuredPartners, and a run of regional deals, positions it to compete on exactly that terrain.
Doyle spent most of his career inside Gallagher’s regional operations, a background that fits a division managing simultaneous integration and growth mandates.
The chairman transition for Ziebell mirrors the structure Gallagher used in 2017, when James W. Durkin Jr., who had led the benefits division since 1985, moved to chairman as Ziebell took the president role of the division. Gallagher tends to retain institutional knowledge during leadership transitions rather than engineering clean breaks, and the pattern reflects how much continuity matters when long-standing client relationships are at stake alongside large-scale integration.
The US group benefits brokerage industry is at an inflection point, with consolidation reshaping the competitive landscape and employee benefits agencies accounting for roughly 13% of US and Canadian insurance agency M&A deals tracked by OPTIS Partners in 2025. Gallagher has been among the most active buyers in that cycle, and whoever runs its benefits division sets one of the more visible reference points for where the market’s largest platforms are headed.
