Alta Services LLC, formerly McPhaden Rehabilitation Services, Inc. "MRSI" and Managed Care Services, Inc. "MCSI" has a history that dates to the late 1970's. Alta began as an onsite case management and utilization review company providing services to injured workers and automobile accident victims. Initially these services focused on the eastern Pennsylvania market and gradually spread to the surrounding geographic areas including New York, New Jersey, Delaware and Maryland. By the early-nineties, Alta had established itself as a leading case management and auditing company for the New Jersey, New York and Philadelphia metropolitan property and casualty markets. Alta's New Jersey operations continued to flourish, developing new services such as bill review, auditing and preferred provider organization (PPO) network repricing. Over the past two decades, Alta has developed a significant customer base of "A" rated insurance companies as well as self-insured businesses.

On June 30, 1999 Alta Services was granted dual accreditation by URAC for Health Utilization Management and Workers' Compensation Utilization Management.