[3] By adding 99 centers and more than doubling U.S. HealthWorks operations, it became one of the largest provider networks in the United States, along with Concentra.
[11] In October 2011, it acquired four Nashville-based medical centers and seven worksite locations operated by Tennessee Urgent Care Associates.
[13] In January 2013, it acquired three Advanced Occupational Medicine Specialists (AOMS) healthcare centers in the Chicago region.
[14] In June 2013, it acquired the assets of seven OHS-Compcare clinics and two worksites in the Kansas City area.
It was alleged that the firm did not always file a "Doctor's First Report of Injury" as required by California law, which would distort the risk experience used by insurance underwriters to calculate premiums.