Michigan Radio reviewed records and reported teachers must have a valid certification or permit from the Michigan Department of Education.
A financial emergency prompted the appointment of a financial manager by the state who ordered the school district to stop providing educational services. He laid off everyone in the district and hired Mosaica Education Inc. to run the school system.
Mosaica Education CEO Mike Connelly said the company believed the teachers were eligible for certification when they were hired.
In Muskegon Heights, public records from January show at least eight teachers weren't certified. That's more than 10 percent of staff in those records.