When a federal law conflicts with a state law, the Constitution states that the federal law supersedes the state law. So, for example, several states have laws setting the state minimum wage lower than the federal minimum wage. In this case, the federal law preempts the state law, and employers in that state are required to pay the federal minimum wage. Labor law is one of the few areas in which the preemption doctrine doesn’t apply. As explained above, when federal and state labor laws conflict, the DOL requires employers to follow the law that protects employees the best.