The FMLA allows eligible employees to take leave to care for an immediate family member. What exactly is an immediate family member?
Generally, an employee’s spouse, children (son or daughter), and parents are immediate family members for purposes of the FMLA. In-laws are not included as parents. And sons and daughters do not include individuals 18 or over unless they are “incapable of self-care” because of a mental or physical disability that limits one or more of the “major life activities” as those terms are defined in ADA-related regulations.
Source: U.S. Department of Labor, Employment Standards Administration, Wage and Hour Division, FMLA Compliance Guide, December 1998.