29 U.S.C. § 218d — Breastfeeding accommodations in the workplace

(a) In general: An employer must provide (1) reasonable break time for an employee to express breast milk for their nursing child, for one year after birth, each time the employee needs to; and (2) a place — not a bathroom — shielded from view and free from intrusion by coworkers or the public, for that purpose. (b) Compensation: (1) Generally, an employer doesn't have to pay the employee for the break time provided under (a)(1), unless federal or state law or a local ordinance requires it. (2) But if the employee isn't completely relieved from duty during the whole break, that time counts as hours worked and must be paid. (c) Small-employer exemption: An employer with fewer than 50 employees isn't subject to this section if meeting its requirements would cause undue hardship — meaning significant difficulty or expense given the employer's size, financial resources, nature, or structure. (d) Air carrier crewmembers: (1) An air carrier employer isn't subject to this section for an employee who is a crewmember. (2) "Air carrier" and "crewmember" carry the meanings given in Title 49 and federal aviation regulations. (e) Rail carriers: (1) Generally, a rail carrier employer is subject to this section. (2) But for an employee who's a member of a train crew moving a locomotive or rolling stock, or who maintains the right of way, the rail carrier is subject to this section only if compliance doesn't (A) require significant expense — such as adding a crew member, removing or retrofitting seats, or modifying a locomotive or rolling stock — or (B) create unsafe conditions for a right-of-way employee. (3) Installing a curtain or other screening isn't a significant expense. (4) Defined terms — "employee who maintains the right of way," "rail carrier," and "train crew" — each point to specific federal transportation provisions. (f) Motorcoach operators: (1) Generally, a motorcoach services operator is subject to this section. (2) But for an employee involved in moving a motorcoach, the operator is subject to this section only if compliance doesn't (A) require significant expense — such as removing or retrofitting seats, modifying the motorcoach, or making unscheduled stops — or (B) create unsafe conditions for an employee or passenger. (3) It's not a significant expense to (A) install a curtain or screening if an employee requests it, or (B) let an employee use scheduled stop time to express milk. (4) Defined terms cover "motorcoach," "motorcoach services," and "motorcoach services operator." (g) Notice before suing: (1) Except as in (2), before suing under section 216(b) over a violation of subsection (a)(2) — the private-space requirement — an employee must (A) notify the employer that the required place wasn't provided, and (B) give the employer 10 days to come into compliance. (2) That notice isn't required if (A) the employee was fired because they requested the break time or place, or opposed employer conduct related to this section, or (B) the employer has already indicated it doesn't intend to provide the required place. (h) Interaction with other law: (1) This section doesn't preempt a state law or local ordinance that provides employees greater protection. (2) This section has no effect on the separate preemption of state law under subtitle IV, V, or VII of Title 49.