Healey said the department, under President Donald Trump, has not processed a single student loan discharge application for former Corinthian students.
"(Attorneys General are) suing Secretary DeVos and the U.S. Department of Education to protect students who have waited in vain for the department to follow the law and give them the relief they've been promised," Healey said in a conference call with reporters.
Healey was joined in the suit by attorneys general from New York and Illinois, with a similar suit being brought in California by Attorney General Xavier Becerra. All the attorneys general are Democrats.