The U.S. Department of Education has fined for-profit school Grand Canyon University $37.7 million, the largest enforcement fine ever issued.

The department’s Federal Student Aid found GCU lied to more than 7,500 former and current students about the cost of its doctoral program over several years, advertising lower costs than what 98% of participants ended up paying. Phoenix-based Grand Canyon denies the allegations.

“GCU lied about the cost of its doctoral programs to attract students to enroll,” FSA Chief Operating Officer Richard Cordray said in a statement. “GCU’s lies harmed students, broke their trust, and led to unexpectedly high levels of student debt.”

According to the most recent data, GCU enrolled more than 100,000 students through in-person and online instruction. In the past four years, it has accounted for the most federal aid of all participating institutions, feds said. According to FSA, GSU claimed certain doctoral program costs between $40,000-$49,000. In reality, FSA said GCU’s own data showed less than 2% of graduates completed their degree within the advertised costs. More than three-quarters of the graduates ended up paying an additional $10,000-$12,000, roughly a 25% increase, depending on the program.

Fine-print disclosures on materials disclosing the extra costs were not sufficient, FSA said.

GCU has 20 days to appeal the decision after it was entered.

In its statement, GCU said the penalty is “further evidence of the coordinated and unjust actions the federal government is taking against the largest Christian university in the country.

“Grand Canyon University categorically denies every accusation in the Department of Education’s statement and will take all measures necessary to defend itself from these false accusations,” the school said.

In addition to the fines, GCU must now tell students the average total tuition and fees and provide quarterly reports to officials.