Under the Supremacy Clause, federal law preempts state law that conflicts with it. Express preemption arises from statutory language, field preemption from a comprehensive federal scheme, and conflict preemption where compliance with both is impossible or state law obstructs federal objectives.
Impossibility preemption applies where a defendant could not comply with a state duty without violating federal requirements.
Alternative Names:
Preemption Doctrine, Supremacy Clause Preemption
Why it Matters?
Preemption is among the most powerful defenses in regulated-industry litigation because it defeats claims entirely rather than reducing them. It is central to pharmaceutical and medical device defense, and it appears in transportation, banking, and consumer contexts. Because it presents a pure question of law, it is well suited to early dispositive motion practice before discovery cost accumulates.
Frequently Confused with
Related terms
Frequently asked questions
What are the types of preemption?
Is preemption decided early?
