BOISE, Idaho (AP) — State auditors say the contractor managing mental health and substance treatment for Idaho's poor has helped reduced the use of community-based rehabilitation services, which in turns has significantly lowered Medicaid costs.

Lance McCleve from Idaho's Office of Performance Evaluations told state lawmakers Monday that Medicaid spending for community-based rehabilitation, also known as psychosocial rehabilitation, ballooned from $8.3 million in 2001 to $76.1 million in 2012. This led state health officials and lawmakers to raise concerns that providers were overusing costly rehabilitation for higher Medicaid reimbursements.

In 2013, Idaho began paying Optum — a unit of UnitedHealth Group — $10.5 million a month to administer Medicaid's outpatient behavioral health services. Auditors say the three-year contract has been successful in lowering Medicaid costs and encouraging providers to focus on appropriate services for patients.