A new audit suggests that many people who enrolled in public health insurance through MNsure last year might not have qualified, driving as much as $271 million in overpayments during a five-month period.
The report issued Thursday by Legislative Auditor James Nobles looked at a sample of cases from early 2015 and found errors in 38 percent of those who enrolled through the state's health insurance exchange in either the Medical Assistance or MinnesotaCare programs.
Auditors applied the error rate to a larger group that enrolled through MNsure to project the potential cost.
"We all know there's going to be some error, but this is higher than an acceptable error rate," said Cecile Ferkul, the deputy legislative auditor.
The state Department of Human Services (DHS), which uses the MNsure system to run the programs, said the report points to issues that it continues to address, although officials questioned whether the audit overstates the problem.
The auditor's report focused on the portion of MNsure used for the state's public health insurance programs, which generally provide coverage for lower-income Minnesotans.
As of March 2015, more than half of the 870,000 people enrolled in public health care programs had done so through the MNsure system, according to the audit.
It looked at a sample of 157 enrollments through MNsure between January and March 2015, and found that 59 of them were not eligible for the public program from which they were receiving coverage.