Like other electronic health record systems, EPAS is intended to provide a single health record for all patients with a single point of access.
Adam Internet's role will be to replicate EPAS at its tier-3 data centre (currently being expanded) in order to provide high availability.
The main system will run at South Australia's Glenside data centre.
David Johnston, executive director of e-health services at SA Health, said "The EPAS project is an important initiative for the future of public health care in South Australia.
"This is a complex project that will only be a success if data management and storage is robust.
Greg Hicks, executive chairman of Adam Internet, said "Adam Internet is thrilled to be part of such an important project for South Australia.
"This initiative not only puts the Government of South Australia and SA Health at the forefront of innovative care but will mean a far more efficient health care system for the future."
The contract between SA Health and Adam Internet has a term of 10 years.