San Francisco on Tuesday became the first place in the country to require that employers provide six weeks of fully paid leave to new parents.

The ordinance, approved by the Board of Supervisors, covers employees in San Francisco county and city who wish to take time off to care for a newborn baby, newly adopted child, new foster child, or to attend to an ill family member.

The law, which goes into effect next year, intially applies to employers with 50 or more workers. Beginnining July 1, 2017, it extends to employers with 20 or more employees.

The sweeping benefit is the first of its kind in the country, which remains the only industrialized nation not to guarantee paid parental leave to all workers. California offers six weeks of family leave at 55 percent of pay—one of three states to enact paid leave policies, according to the National Partnership for Women and Families.

New York’s governor this week signed a $15 minimum wage law that includes a new provision for 12 weeks of paid parental leave—a measure that offers longer coverage, but fewer financial benefits than San Francisco’s. New York’s policy phases in paid parental leave beginning in 2018, and offers workers a maximum of 67 percent of their average weekly wage when fully implemented in 2021.

“The vast majority of workers in this country have little or no access to paid parental leave, and that needs to change,” San Francisco Supervisor Scott Wiener, who sponsored the measure, said at a news conference before the vote, as the Associated Press reported.

Under San Francisco’s ordinance, employers will now make up the difference between what the state covers (55 percent) and what the law now mandates.

San Francisco is a leader in pro-worker measures, requiring paid sick leave and passing a law to lift the minimum wage to $15 an hour by July 2018. California’s governor on Monday signed an unprecedented statewide $15-per-hour minimum wage bill that is expected to raise the wages of more than six million people who work in the state by 2023.

Small business owners in San Francisco have complained that the paid leave ordinance is the latest in a string of mandates that burden their companies, according to the Associated Press. Business groups like the Bay Area Council, the members of which include Google and Facebook, voiced support for paid parental leave.

Documents leaked to the Center for Media and Democracy this week show that most business leaders support parental leave policies and boosting the minimum wage, despite fierce opposition to those measures from chambers of commerce.

“Paid parental leave increases the probability that employees will return to work, be more productive, and earn higher wages,” Jim Wunderman, president and CEO of the Bay Area Council, told the Associated Press. “That is good for business and for families.”

California’s paid leave program is financed through the state insurance program. The California Employment Development Department approved roughly 1.8 million paid family leave claims totaling $4.6 billion in 2014. About nine out of ten claimants took leave to bond with a new child.

A 2014 report by the California Senate Office of Research indicates that claims filed by highly paid employees outnumbered claims filed by workers who earn less, suggesting that the state’s low-wage workers can’t afford to take time off for their families.

Vicki Shabo, vice president of the National Partnership for Women and Families, said the San Francisco measure could help boost momentum at the national level, where federal law provides for 12 weeks of unpaid leave.

“It’s great to see local leaders stepping up,” Shabo told the Guardian, noting that California’s first-of-its-kind law served as a model for other states. “There’s a growing consensus that the nation must do something to address this.”