The Minnesota Department of Human Services is losing another member of its executive leadership team, just days before a new commissioner will take the helm at the troubled agency.

Marie Zimmerman, assistant commissioner for health care and director of the state Medicaid program, will leave DHS on Sept. 10, according to an email she sent to colleagues Friday.

“I’m writing to share that I will be leaving DHS to continue my passion of serving people covered by Medicaid, consulting with other states and local entities,” Zimmerman said, noting that she is also recovering from injuries sustained in a recent accident.

Marie Zimmerman, assistant commissioner for Health Care and Minnesota’s Medicaid director. (Courtesy photo)

In a separate email to employees, acting DHS Commissioner Pam Wheelock praised Zimmerman as a “driving force behind some of the largest and most consequential reforms in Minnesota’s Medicaid program” since 2011. A total of 1.1 million Minnesotans are enrolled in the sprawling program.

Zimmerman is leaving the agency as it comes under fire for improper Medicaid spending. Minnesota owes the federal government $73 million because DHS improperly dealt out money to certain state chemical dependency treatment providers and overpaid two tribal governments for substance abuse treatment covered under Medicaid.

DHS overpaid the tribes by $25.3 million over the past five years. The agency allegedly advised the tribes to bill for medication that patients took at home, which officials now claim is not eligible for reimbursement. Department officials want the Indian bands to pay back the $25 million even though tribal leaders have produced emails in which the agency appeared to tell them to bill at a rate that caused the overpayments.

DHS separately owes another $48 million because it dealt out Medicaid money to certain drug treatment providers who were not eligible for federal funds. Those payments also occurred over the past five years.

Officials say they will not claw back the $48 million from the providers because the billing error was made by the department. And a DHS spokeswoman said the $48 million repayment was accounted for in the state budget that lawmakers passed in May.

Zimmerman will be the fourth member of the department’s executive leadership to resign in the past two months.