The Composite Health Care System (CHCS) was a medical informatics system designed by Science Applications International Corporation (SAIC) and used by all United States and OCONUS military health care centers. In 1988, SAIC won a competition for the original $1.02 billion contract to design, develop, and implement CHCS.[1]
SAIC later split into two separate organizations, and the company Leidos took control of CHCS and associated systems in 2016.
CHCS (and AHLTA) is being replaced by MHS Genesis, a Cerner product. The last AHLTA servers at MTF's (Military Treatment Facilities) were shut down in early 2024. By October 2024, only a handful of CHCS servers remain on-line, with only 18 host sites compared to 105 host site systems prior to the deployment of MHS Genesis.