Concentra Group Holdings Parent, Inc.
A company that keeps America's workforce healthy: Concentra runs occupational health centers and onsite workplace clinics that treat work injuries, do physicals, and handle drug screens for employers and workers' comp insurers. It traces back to 1979, when a Texas family physician named Richard Rehm founded OccuSystems, later renamed Concentra after a 1997 merger. Its workers' comp care serves around 200,000 employer customers, including every Fortune 100 company.