Gallagher's internship program has operated for roughly six decades and today places several hundred interns each summer across more than 140 office locations in the United States, with a related program operating in Canada. Eligible candidates are generally rising sophomores and juniors.

During the internship, participants are placed within local branch offices where they gain exposure to insurance brokerage, risk management, and client consulting work, and take on responsibilities tied to sales and client service rather than just administrative tasks. Interns receive mentorship from established professionals within their branches and are given structured opportunities to learn the fundamentals of the insurance and risk management business, including building client relationships and understanding how brokerage and consulting services are delivered. The program is a pathway to potential full-time employment and long-term career development, and it has historically served as an entry point for people who later became leaders within the company.