Express Preemption

Definition / Rule

Express preemption occurs when Congress explicitly states in a federal statute that federal law supersedes, displaces, or nullifies state law in a defined domain. Under the Supremacy Clause (Art. VI, cl. 2), federal law is the supreme law of the land, and state law that conflicts with federal law is preempted. When Congress includes an explicit preemption clause, courts must identify the scope of that clause and determine what state law it displaces.

Analytical Framework

Step 1: Identify the Preemption Clause

What does the statute’s text say about preemption? Preemption clauses vary enormously: some are broad (“any state law relating to…”), others narrow (“any state law that is different from or in addition to this Act”).

Step 2: Determine the Scope of Preemption

What category of state law does the clause cover? Courts apply standard tools of statutory interpretation — text, structure, purpose, legislative history — to define the preemption clause’s scope. Ambiguous preemption clauses are often narrowly construed in areas of traditional state regulation.

Step 3: Identify Any Savings Clauses

Many statutes include savings clauses that expressly preserve certain categories of state law despite the preemption clause. Courts must reconcile preemption clauses with savings clauses, which can create interpretive difficulty.

Step 4: Apply the Presumption Against Preemption

In areas of traditional state police power (health, safety, tort law), courts apply a presumption against preemption: ambiguous federal statutes are not presumed to preempt state law (Medtronic, Inc. v. Lohr). The presumption may be weaker when Congress has expressly addressed preemption.

Key Cases

• Medtronic, Inc. v. Lohr (1996) — Federal Medical Device Amendments preemption clause narrowly construed; state common law tort claims not preempted. Stressed the presumption against preemption and the importance of savings clauses.
• Riegel v. Medtronic, Inc. (2008) — Pre-market approved medical devices ARE preempted from state tort claims by MDA preemption clause; distinguished Lohr (510(k) clearance vs. full pre-market approval).
• Cipollone v. Liggett Group (1992) — Federal cigarette labeling law preempted state failure-to-warn claims but not fraudulent misrepresentation claims; clause’s scope determined by text.
• Bates v. Dow Agrosciences (2005) — FIFRA preemption clause narrowly construed; state tort claims not preempted if they impose parallel (not different) requirements.

Savings Clauses

Savings clauses limit the preemption clause’s reach. Common types:

• General savings clause: “Nothing in this Act shall be construed to preempt any state law…”
• Tort savings clause: Preserves state common law tort claims
• Concurrent enforcement clause: States may enforce their own parallel requirements

Tension between preemption and savings clauses is a major source of litigation; courts must read them together.

Policy

Federal uniformity: Express preemption promotes regulatory uniformity, particularly important for national markets and products regulated by federal agencies.

State experimentation: Presumption against preemption respects states’ traditional role as laboratories for regulatory innovation and preserves state remedies for injured parties.

Democratic legitimacy: Congress bears responsibility for preemption decisions it makes explicitly; courts should enforce those decisions without expanding them beyond Congress’s actual choice.