Back in 2010, when the The Patient Protection and Affordable Care Act went into effect, the Fair Labor Standards Act (FLSA) was amended to require a "reasonable break time for an employee to express breast milk for her nursing child for 1 year after the child's birth each time such employee has need to express the milk."
Generally, employers are not required to compensate an employee for the break time to express milk, and an employer with fewer than 50 employees does not have to comply with the rule if it would pose an undue hardship.
One more minor caveat -- of which I must admit, I was not aware -- the law only covers non-exempt employees. (Although, I imagine that most businesses afford the same dignity to exempt employees too).
But just in case, Senator Jeff Merkley (OR-D) has introduced the Supporting Working Moms Act of 2013, which will further amend the FLSA to provide exempt moms with the same PPACA/FLSA right to express breast milk at work provided to their non-exempt counterparts.
** Must fight urge to...aw hell **
The Supporting Working Moms Act is co-sponsored by Senators Tom Harkin (D-IA) and Elizabeth Warren (D-MA).
Identical legislation was introduced in the House by Congresswoman Carolyn Maloney (D-NY). In 2011, Ms. Maloney introduced the Breastfeeding Promotion Act of 2011, which would have amended both the FLSA and also changed Title VII of the Civil Rights Act of 1964 to preclude employers from discriminating against those who lactate. Title VII already covers discrimination on the basis of gender and sex.
(And last time I checked, only women lactate)