SEIU 1199, the healthcare workers union whose endorsements are coveted by campaigns due to its ability to deploy large numbers of canvassers, plans to wait to announce its backing until after the Sept. 14 preliminary winnows the number of mayoral candidates to two.

The Quincy-based union’s board recently made the decision to see “where people land in the preliminary,” according to FayeRuth Fisher, the union’s Massachusetts political director.

“People felt good about making an endorsement after that because there are a lot of candidates we’ve worked with,” she said.

The union has more than 5,000 members who live in Boston. Its members, who number at more than 70,000 statewide, seek a broad agenda that includes access to affordable health care and housing, as well as racial and social justice, according to Fisher.

Along with canvassers, 1199 has a political action committee with $3 million in cash on hand. The union didn’t rule out sending a super PAC into the race, as the hotel workers union UNITE HERE Local 26 has deployed on behalf of Acting Mayor Kim Janey.

Boston has five major candidates running for mayor: Janey, City Councillors At-Large Annissa Essaibi George and Michelle Wu, District 4 Councillor Andrea Campbell, and former city economic development official John Barros.

Other unions have jumped into the race. The property service workers of SEIU 32BJ and the city workers union SEIU Local 888 are backing Janey, while Teamsters Local 25 endorsed Wu. The Boston Emergency Medical Services union and firefighters Local 718 which have endorsed Essaibi George.

SEIU 1199 sat out the 2013 mayoral preliminary, which featured 12 candidates vying to replace Mayor Thomas Menino. For the November final, the union endorsed Marty Walsh, a state representative and labor leader, over City Councillor At-Large John Connolly.

The union has also sat out more recent high-profile Massachusetts races, including Joe Kennedy III’s unsuccessful primary challenge of US Sen. Ed Markey, Ayanna Pressley beating out Congressman Michael Capuano, and Republican Gov. Charlie Baker fending off a challenge from Democrat Jay Gonzalez.

Fisher said the union was focused on mobilizing against the Trump administration and defending the Affordable Care Act, also known as Obamacare.

“We are now in a different place,” she told the Reporter.