Thousands of University of Maryland students were incorrectly charged for school health insurance Wednesday despite having submitted waivers that should have exempted them from being enrolled.

9,390 students who had already provided proof of their health insurance were erroneously charged. All charges were reversed after they were discovered the next day, said University Health Center director David McBride.

McBride said the incident stemmed from a paperwork mix-up by the insurance broker for the Student Health Insurance Plan.

The broker, Academic HealthPlans, provided the university with a list of people who it said had not yet waived the coverage. But it sent the wrong list — providing the school instead with the names of people who had waived the coverage.

“Before being aware of the error, as is our practice, we posted the premium to the accounts of those individuals,” McBride said.

AHP sent out an email about the error to those affected the day after the charges were posted, McBride said. AHP wasn’t available for comment before the time of publication.

When Matthew Kasa, a senior computer science major, got that email, his first thought was, “Oh, they made another mistake.”

Kasa had been charged $1,298, a screenshot of his account showed, despite having submitted his SHIP waiver.

“I’m glad the university caught the error but at the same time the error should not have occurred in the first place,” Kasa said.

Kasa noted that by the time he had verified his student account had been wrongly charged, he had already been credited back the same amount.

Kasa said a similar set of events happened last year, when he submitted his waiver before the deadline but was notified that he had been charged anyway. He was later refunded his money.

But McBride said this was the first time students were mistakenly charged. He offered to investigate any past incidents, if provided more information.

McBride said that this was the first year with a new broker for the SHIP plan, and that with “any new relationship with a vendor, there are often challenges.”

“Given this error, we’ll be doing extra outreach to students and families to ensure that they are aware of the need to enroll or waive,” McBride said.