Men’s basketball players at Dartmouth College, an Ivy League school in New Hampshire, voted on Tuesday to form a union, in a potentially transformative moment for U.S. college athletics.

The team voted 13-2 to join an affiliate of the Service Employees International Union, which had petitioned to represent the players last year, according to results tallied by the National Labor Relations Board.

The vote comes amid a broader effort to roll back restrictions on compensation for student athletes, such as a bar on athletes profiting from the commercial use of their name, image and likeness.

Athletic programs generate an estimated $8.5 billion in revenue for top schools each year, and less than 7% of that money is passed on to athletes in the form of scholarships and stipends, according to a 2020 report by the National Bureau for Economic Research.

Dartmouth and the union did not immediately respond to requests for comment.

Dartmouth last week said it planned to challenge the results of the election and asked the labor board to impound the election ballots while it decides whether the players were eligible to vote in the first place.

In a ruling last month, a regional director with the labor board said basketball players were Dartmouth’s employees because the school’s basketball program generates publicity, alumni engagement and financial donations and the school controls the work performed by players.

The ruling allowed them to vote on unionizing.

Forming a union will allow Dartmouth basketball players to bargain collectively with the school over compensation and working conditions, such as practice schedules, travel policies and discipline from coaches. It could also spur student-athletes at other schools around the country to unionize.

The decision teeing up the election was the first of its kind since the labor board’s general counsel, Jennifer Abruzzo, issued a memo in 2021 arguing that many college athletes should be classified as school employees. The memo focused on athletes who receive scholarships as a form of compensation. Dartmouth and other Ivy League schools do not award athletic scholarships.

Abruzzo, an appointee of President Joe Biden, said at the time that her office would bring complaints against colleges that interfere with players’ organizing efforts. The general counsel acts as a prosecutor, bringing cases to the five-member labor board, whose decisions can be appealed in federal appeals courts.

The University of Southern California and the National Collegiate Athletics Association, the governing body for college sports, were hit with a complaint from Abruzzo’s office last May, claiming they had blocked student athletes from unionizing by not treating them as the school’s employees. The case is pending.

The five-member labor board, which currently has a Democratic majority and one vacancy, has never directly addressed whether college athletes can be considered school employees.

In 2014, football players at Northwestern University in Evanston, Illinois, became the first college athletes to vote in a union election, but the ballots were impounded due to a legal challenge by the school.

The board ultimately ruled that it could not decide whether the players were eligible to unionize because doing so would impact all of the schools Northwestern competes against, including many state-run colleges. The board’s enforcement powers only extend to private employers.

That may not be an issue in the Dartmouth case because the Ivy League conference is made up of only private schools and rarely plays against public colleges.