In a decision published on June 22, 2010, the U.S. Department of Labor formally clarified that the phrase "a parent standing in loco parentis," to a child for purposes of FMLA leave encompasses all individuals who exercise day-to-day responsibilities to care for and financially support a child, regardless of that person's biological relationship to the child.
An eligible employee may request FMLA leave for the birth of a son or daughter or to care for a son or daughter with a serious health condition. The FMLA statute defines "son and daughter" as including within its scope "a child of a person standing in loco parentis." The DOL regulations further define "in loco parentis" to include those indiviuals who provide day-to-day care and financial support for a child. In its June 22 decision interpreting this regulation, the Department formally stated that "employees who have no biological or legal relationship with a child may nonetheless stand in loco parentis to the child and be entitled to FMLA leave." In providing examples of this interpretation, the Department stated that "an employee who will share equally in the raising of an adopted child with a same sex partner, but who does not have a legal relationship with the child, would be entitled to leave to bond with the child . . . because the employee stands in loco parentis with the child." The Department also noted that in situations where a child's biological parents divorce and then each remarries, the two biological parents and the two non-biological step-parents would all have "equal rights to take FMLA leave to care for the child."
The Department also noted that when an employer has questions as to whether an employee's relationship is covered under the FMLA, the employer may require the employee to provide "reasonable documentation or statement of the family relationship."
A link to the full Department of Labor decision can be found here: http://www.dol.gov/whd/opinion/adminIntrprtn/FMLA/2010/FMLAAI2010_3.pdf