Title 28, Judiciary and Judicial ProcedureRelease 119-102

§2403 Intervention by United States or a State; Constitutional Question

Title 28 › PART VI — PARTICULAR PROCEEDINGS › CHAPTER 161 — UNITED STATES AS PARTY GENERALLY › § 2403

Last updated Aug 21, 2026|Official source

Summary

If a federal law’s constitutionality is questioned in a U.S. court and the United States is not already involved, the court must tell the U.S. Attorney General and let the United States join the case. The United States can present evidence that would be allowed and argue the issue. It has the same party rights and may face the same cost rules as needed under other laws. If a state law’s constitutionality is questioned and the state is not a party, the court must tell the state’s attorney general and let the state join, present admissible evidence, and argue, with the same party rights and cost rules as allowed by law.

Full Legal Text

Title 28, §2403

Judiciary and Judicial Procedure, Source: USLM XML via OLRC

(a)In any action, suit or proceeding in a court of the United States to which the United States or any agency, officer or employee thereof is not a party, wherein the constitutionality of any Act of Congress affecting the public interest is drawn in question, the court shall certify such fact to the Attorney General, and shall permit the United States to intervene for presentation of evidence, if evidence is otherwise admissible in the case, and for argument on the question of constitutionality. The United States shall, subject to the applicable provisions of law, have all the rights of a party and be subject to all liabilities of a party as to court costs to the extent necessary for a proper presentation of the facts and law relating to the question of constitutionality.
(b)In any action, suit, or proceeding in a court of the United States to which a State or any agency, officer, or employee thereof is not a party, wherein the constitutionality of any statute of that State affecting the public interest is drawn in question, the court shall certify such fact to the attorney general of the State, and shall permit the State to intervene for presentation of evidence, if evidence is otherwise admissible in the case, and for argument on the question of constitutionality. The State shall, subject to the applicable provisions of law, have all the rights of a party and be subject to all liabilities of a party as to court costs to the extent necessary for a proper presentation of the facts and law relating to the question of constitutionality.

Legislative History

Notes & Related Subsidiaries

Historical and Revision Notes

Based on title 28, U.S.C., 1940 ed., § 401 (Aug. 24, 1937, ch. 754, § 1, 50 Stat. 751). Word “action” was added before “suit or proceeding”, in view of Rule 2 of the Federal Rules of Civil Procedure. Since this section applies to all Federal courts, the word “suit” was not required to be deleted by such rule. “Court of the United States” is defined in section 451 of this title. Direct appeal from decisions invalidating Acts of Congress is provided by section 1252 of this title. Changes were made in phraseology.

Editorial Notes

Amendments

1976—Pub. L. 94–381, § 5(b), inserted “or a State” after “United States” in section catchline. Subsecs. (a), (b). Pub. L. 94–381, § 5(a), designated existing provisions as subsec. (a) and added subsec. (b).

Statutory Notes and Related Subsidiaries

Effective Date

of 1976 AmendmentAmendment by Pub. L. 94–381 not applicable to any action commenced on or before Aug. 12, 1976, see section 7 of Pub. L. 94–381, set out as a note under section 2284 of this title.

Reference

Citations & Metadata

Citation

28 U.S.C. § 2403

Title 28, Judiciary and Judicial Procedure

Last Updated

Aug 21, 2026

Release point: 119-102