A three-day arbitration hearing this week wasn’t enough time to solve a labor dispute between the Clark County School District and the teachers union.

Additional arbitration hearing dates have been scheduled for Sept. 13, 14 and 15, said Amber Lopez Lasater, a spokesperson for the Clark County Education Association, the union that represents teachers and other licensed professionals in the district.

Lopez Lasater said the union couldn’t discuss why the extra hearing dates are necessary, citing the ongoing arbitration. Clark County School District officials also declined to comment.

Contract negotiations between the school district and teachers reached an impasse earlier this summer, but an arbitrator ordered the parties back to the negotiating table with the assistance of a mediator. Those talks didn’t prove successful, hence the arbitration hearings that began Monday and ran through Wednesday.

The union has requested a roughly $80 million package that includes 3 percent step pay increases as well as additional premium contributions to teachers’ health care.

The school district sent a memo to licensed professionals earlier this month explaining why it has called for a pay freeze for the 2017-2019 academic year.

“Right now, CCSD is working to address a $45 million deficit in our 2017-2018 budget — before considering raises to any of our employee groups in 2017-2018,” district officials wrote in the staff memo. “This is due to a variety of factors, including less-than-expected revenues from the state, and changes to the CCSD budget to comply with the state-mandated reorganization.”

The fate of teachers’ health care, however, may be the thorniest issue of the labor dispute. The school district has proposed moving teachers from the beleaguered Teachers Health Trust to fully-insured UnitedHealthcare plans similar to the ones provided for support staff and school police.

But union officials insist the Teachers Health Trust — the nonprofit organization that oversees health care for roughly 18,000 Clark County teachers and licensed professionals and their 22,000 dependents — can deliver quality medical care once again if the school district adequately funds it.

The health-care situation has triggered a fiery debate. Some educators say they’re better off with the trust as opposed to a private-insurance company, while others have bemoaned frequent insurance hassles and problems obtaining their medications through the nonprofit organization.

The school district already lost one arbitration case this year. An arbitrator ruled in favor of the union representing school administrators and principals in May, saddling the district with $19.5 million in retroactive pay increases.