## Facts

- The United States brought civil antitrust actions against American Pipe & Construction Co. and other defendants alleging price-fixing in the concrete and steel pipe industry; final consent judgments were entered in May 1968.
- Within one year after the consent judgments, Utah filed a Sherman Act treble-damages action as a Rule 23 class action on behalf of various public entities and other Western States.
- The filing was timely under the Clayton Act’s four-year limitations period as suspended by Clayton Act § 5(b) during the government proceedings and for one year thereafter.
- The district court later determined the case could not proceed as a class action because the proposed class did not satisfy Rule 23(a)(1)’s numerosity requirement.
- More than 60 putative class members moved to intervene as plaintiffs shortly after class certification was denied.
- The district court denied intervention, concluding the statute of limitations had run and was not tolled by the earlier class-action filing.

## Issues

1. Whether the filing of a putative class action under Rule 23 suspends the statute of limitations for all asserted members of the proposed class while class certification is pending.
2. If certification is denied, whether those asserted class members may timely intervene or file individual actions after the limitations period would otherwise have expired.

## Decision

- The Supreme Court affirmed the judgment allowing intervention.
- The Court held that commencement of a putative class action tolls the applicable statute of limitations for all asserted class members who would have been parties if the class had been certified.
- Because defendants received timely notice through the class complaint of the substantive claims and the generic identities of potential plaintiffs, tolling did not unfairly surprise or prejudice defendants.
- The Court rejected the argument that Clayton Act § 5(b) displaced judicial tolling; the tolling rule was treated as consistent with federal procedural policy and equitable principles.

## Legal Principles

- Filing a complaint as a Rule 23 class action suspends the running of the statute of limitations for all asserted members of the proposed class during the pendency of the certification decision.
- After class certification is denied, asserted class members may proceed by timely motion to intervene (and may file individual actions) without having filed protective suits during the certification period.
- Judicial tolling in this context is a procedural/equitable doctrine and does not abridge or modify substantive rights created by federal statutes that also contain limitations periods.
- Tolling serves Rule 23’s purposes by avoiding duplicative protective filings and by protecting absent class members who reasonably rely on the pending class action to preserve their claims.

## Conclusion

The Court held that a timely filed putative class action tolls the statute of limitations for all asserted class members until class certification is denied, allowing those members to intervene or sue individually without being barred by limitations during the certification period.


American Pipe & Constr. Co. v. Utah, 414 U.S. 538 (1974)