Regulation FD Disclosure Form 8 K

On September 6, 2024, Arthur J. Gallagher & Co. (the "Company") announced plans to host an investor meeting on Thursday, September 19, 2024. As previously announced, a webcast of the meeting and related presentation materials, including an updated "CFO Commentary," are available through the investor relations page of the Company. The CFO Commentary includes certain estimates relating to 2024 results, net after-taxcash flows from clean energy investments in 2024 and future years, and cautionary language regarding forward-looking statements.