The bill, which Mayor Muriel Bowser has promised to sign, will raise the wage by 2020.

WASHINGTON — The D.C. Council on Tuesday approved a $15-an-hour minimum wage bill.

Mayor Muriel Bowser has promised to sign the measure, which will raise the wage by 2020. In a ceremonial news conference, the mayor and council announced they have come to an agreement on a $15 wage. The council formally voted on the bill Tuesday afternoon.

Minimum wage workers in the District currently make $10.50. That rate will increase to $11.50 in July under legislation signed in 2014 by Bowser’s predecessor, Vincent Gray.

“In addition we’ll have a tipped minimum wage that will increase to $5 in 2020. And thereafter, it will increase in pursuant to the Consumer Price Index,” said at-large Council member Vincent Orange before the vote.

The debate over whether to raise the wage further centered around guaranteed compensation for workers who rely on tips. Orange told the council before offering an amendment to address tipped workers’ concerns, there have been lengthy discussion over the tipped wage between council members, the mayor, workers and business owners.

“The fight for 15 is something we’ve been behind all along,” said restaurant owner Andy Shallal who operates Busboys & Poets as well as other businesses in D.C.

Shallal said he is concerned about the effect a change in payroll combined with paid leave and family leave will have on businesses that operate close to their bottom line.

“We’ve been outspoken of the idea of eventually eliminating the tipped wage. But all these things coming at the same time, especially for businesses that have a low-profit margin like restaurants, can be devastating. We have to be mindful of how we do it and move forward with this,” Shallal said.

Some critical of raising the wage say the costs incurred by businesses will be passed on to customers.

For other small businesses, raising the minimum wage could help with employee retention and hiring.

“It’s easy for businesses to understand where the wage structure is going to be and it’s predictable and it does attract the best talent possible. So it certainly does make it competitive with surrounding regions,” said Bryan McGannon, policy director for the American Sustainable Business Council.

While offering her support of the bill, Ward 3 Council member Mary Cheh expressed concerns over the lack of comprehensive studies supporting a $15 wage and that there are residents who are experiencing homelessness despite having paying jobs.

“The problem is it can never be fully enforced and there will always be a slice of workers who won’t get minimum wage. And it’s especially hard on women in the tipped industry, 28 percent of whom live in poverty,” she said.

D.C. joins numerous other cities around the country and the state of California that have approved a $15-an-hour minimum wage.