Janet Brown, a former teacher with the Mecosta-Osceola Intermediate School District, was sentenced to up to 15 years in prison Friday.
In March, a jury found Brown guilty of one count of criminal sexual conduct in the third degree and one count of criminal sexual conduct in the fourth degree.
Brown, 34, sexually assaulted a 16-year-old boy at a private school for troubled teens in November, 2012. School officials said the assault took place after school hours on school property.
Brown will serve a minimum sentence of 36 months.