Arthur J. Gallagher & Co.

Arthur J. Gallagher entered 2020 as the fourth-largest insurance broker globally, with total revenue of approximately $7.2 billion (FY2020 10-K). The company operated two segments: Brokerage (insurance and reinsurance brokerage, consulting) and Risk Management (claims and information management through its Gallagher Bassett subsidiary). Gallagher had long pursued a tuck-in acquisition strategy — buying small and mid-sized independent insurance agencies and integrating them onto its shared services platform — but the company remained significantly smaller than the top three global brokers: Marsh McLennan ($16.7B), Aon ($11.1B), and Willis Towers Watson ($8.9B). The insurance brokerage industry below the top tier is highly fragmented, with thousands of independent agencies generating sub-$50 million in revenue, creating a deep acquisition pipeline. Gallagher's challenge was scaling this acquisition model fast enough to close the gap with larger competitors while maintaining integration discipline and margin expansion.

Gallagher accelerated its long-standing tuck-in acquisition playbook across FY2020–FY2024, completing hundreds of mergers while simultaneously driving organic growth:

• Sustained high-volume tuck-in acquisitions: The company completed roughly 30–50 mergers per year from 2020 through 2024. In FY2024 alone, Gallagher closed 48 mergers representing $387 million of estimated annualized revenue (Gallagher Q4 FY2024 earnings release, January 2025). The Tracxn database records 347 total acquisitions by Gallagher through February 2026.
• Integration onto shared platform: Each acquired agency is integrated onto Gallagher's centralized technology, compliance, and back-office infrastructure. This allows the acquired agency's producers to focus on clients while Gallagher's platform handles administration, carrier access, and regulatory compliance — generating cost synergies that improve margins on the acquired book.
• Organic growth discipline: Alongside acquisitions, Gallagher maintained 7–8% organic revenue growth in its brokerage segment. FY2024 brokerage organic growth was 7.5%, driven by strong client retention, rate increases in hard insurance markets, and cross-selling of additional coverage lines (Gallagher Q4 FY2024 earnings release).
• Transformative AssuredPartners acquisition: In December 2024, Gallagher announced the acquisition of AssuredPartners, a PE-backed commercial middle-market broker with $2.9 billion of pro-forma revenue, for approximately $13.45 billion. This is the largest brokerage acquisition in history, funded by an $8.5 billion stock offering and $5 billion in senior notes (Gallagher press release, December 2024).