Title 28 › PART VI — PARTICULAR PROCEEDINGS › CHAPTER 161 — UNITED STATES AS PARTY GENERALLY › § 2403
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.
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Judiciary and Judicial Procedure, Source: USLM XML via OLRC
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Citation
28 U.S.C. § 2403
Title 28, Judiciary and Judicial Procedure
Last Updated
Aug 21, 2026
Release point: 119-102