There are currently no federal legal requirements for paid sick leave. For companies subject to the Family and Medical Leave Act (FMLA), the Act does require unpaid sick leave. FMLA provides for up to 12 weeks of unpaid leave for certain medical situations for either the employee or a member of the employee's immediate family. In many instances paid leave under an employer’s paid time off (PTO) policy may be substituted for unpaid FMLA leave.

Employees are eligible to take FMLA leave if they have worked for their employer for at least 12 months; have worked for at least 1,250 hours over the previous 12 months; and work at a location where at least 50 employees are employed by the employer within 75 miles.

Because federal law does not require sick leave, if an employee quits their job before using all of their sick leave, the employer is not obligated to pay the employee for that time—unless the employer’s policy or state or other law requires the employer to pay the employee for unused sick leave.

Some states, cities, and counties may have laws that require employers to provide employees with paid sick leave.

In Illinois, while there is no federal mandate for paid sick leave, the Family and Medical Leave Act (FMLA) does require employers to provide up to 12 weeks of unpaid leave for certain medical situations affecting the employee or their immediate family. To be eligible for FMLA leave, employees must have worked for their employer for at least 12 months, accumulated at least 1,250 hours of work in the past 12 months, and work at a location with at least 50 employees within 75 miles. Although federal law does not require paid sick leave, Illinois has its own laws that may require employers to provide paid sick leave. For instance, the Chicago Paid Sick Leave Ordinance and the Cook County Earned Sick Leave Ordinance mandate that employers in those jurisdictions allow workers to earn paid sick leave. If an employee leaves their job without using all their accrued sick leave, the employer is not required to compensate the employee for the unused time unless mandated by the employer's policy or state law. It's important for employees and employers in Illinois to be aware of and comply with any local ordinances that may impose additional requirements for paid sick leave.