Implied Preemption
Definition
The invalidation of a state law that conflicts with a federal law if (1) the federal law occupies the same legislative field in which the state law operates or (2) the state law acts as an obstacle to the purpose or enforcement of the federal law. The first prong is sometimes referred to as field preemption. The second prong is sometimes referred to as either obstacle preemption or conflict preemption. Implied preemption also applies to local laws that conflict with state laws.