AUGUSTA — Most of Maine’s workforce is guaranteed access to paid sick time under a bill Gov. Janet Mills signed into law Tuesday.

The law provides workers with companies that have 10 or more employees an hour of sick time for every 40 hours they work, up to a maximum of 40 hours of time off a year. The paid time could be used for an illness or family emergency.

“Like most Mainers, I don’t know anyone who hasn’t had to take a day off from work to take care of a sick child, family member or had some type of emergency calling them away from work,” Mills said during ceremonial signing of the bill at the State House. “It’s not something people want to do, they value their jobs and in Maine people have a good work ethic and we are proud of that.”

When a worker becomes ill they should be able to take time off without suffering a loss of income, Mills said.

Exempted from the new law are seasonal businesses, those that hire workers for less than 120 days, or those with fewer than 10 workers. The law also requires a worker be employed with a business for at least 120 days before becoming eligible for paid sick time.

It’s not clear how many of the Mainers in workplaces with 10 or more employees already receive paid sick days. The most recent estimate, a study published in 2010 by the Institute for Women’s Policy Research, concluded that 36 percent of the workforce lacked paid sick days.

Mills said the law would cover about 85 percent of Maine’s workforce while exempting more than 40,000 of the state’s 50,792 businesses.

Sponsored by Sen. Rebecca Millet, D-Cape Elizabeth, the law will make Maine the 11th state to have a paid sick time requirement but the only one to allow the time to be used for something other than a personal illness. Maine’s law will not take effect until Jan. 1, 2021, giving employers time to prepare for the new requirements.

The law is the result of a compromise brokered by Mills and business leaders, including representatives of the Maine Chamber of Commerce, which first opposed the bill because it would have included businesses with as few as five employees.

Dana Connors, the chamber president, joined Mills at the bill signing on Tuesday with dozens of others, including co-sponsors of the bill. The new law comes in the wake of a 5-4 vote by the Portland City Council this month to reject a local ordinance requiring the city’s employers to provide paid sick time to workers.

Among other provisions, the new law requires an employer to pay an employee taking earned leave at least the same base rate of pay that employee received immediately prior to taking earned leave and provide the same benefits as those provided under established policies of the employer pertaining to other types of paid leave.

It requires an employee to give “reasonable notice” to their supervisor of their intent to use the leave and specifies that an employee taking earned leave maintains any employee benefits accrued before the date on which the leave commenced.

The law also requires that the leave does not impact an employee’s right to health insurance while it provides the state’s Department of Labor the exclusive authority to develop rules to implement and enforce the law.

Those who testified in support of the new law said it would allow workers to get well enough to go back to work or to take care of a sick child without the fear of losing wages.

Ann Marshall, a Waldo resident, wrote in a letter to lawmakers that many parents without paid sick leave are forced to send sick children to school because they’re afraid of losing their jobs if they call in sick.

“Often, they medicate their feverish children with a dose of Tylenol and off to school they go,” Marshall wrote. “This may seem heartless, but it’s reality. It may work more than likely for that episode, but what it does for the child and the whole school community is to put everyone at risk of becoming the target of viruses and bacteria. Multiply that one episode daily and the whole community suffers.”

Another bill moving before the Legislature, sponsored by House Speaker Sara Gideon, D-Freeport, would require businesses to offer employees up to 12 weeks of partially paid family leave or 20 weeks of medical leave.

That bill would be funded by a new payroll tax on wages of about 0.77 percent that would generate about $145 million a year for the proposed Family and Medical Leave Insurance Fund. The bill has yet to be voted on by the Legislature’s Labor and Housing Committee. An aide for Gideon said the committee was expected to work on the bill again this week, possibly on Thursday.