BOISE, Idaho (AP) — A new report takes aim at the nation’s largest for-profit online education provider and finds students taking K12 Inc. classes in Idaho and four other states are falling more behind in math and reading than their traditional school counterparts.

The study was released Wednesday by the National Education Policy Center at the University of Colorado Boulder. Along with lagging test scores, the report says the rate at which K12 students graduate on time is far lower than in regular schools.