In a decision filed on May 20, 2016 and amended on July 27, 2016, the US Court of Appeals for the Ninth Circuit in Smith v. Los Angeles Unified School Dist., held that the district court abused its discretion in denying the appellant's motion to intervene because it did not apply the appropriate standard regarding timeliness ( (9th Cir. Jul. 27, 2016)).

The appellants, a sub-class of disabled children, sought to intervene in a class action challenging the special education policies in Los Angeles public schools. The plaintiffs and defendants had renegotiated a settlement, and the new agreement resulted in the elimination of special education centers that the sub-class preferred to general education facilities. The sub-class moved to intervene under Federal Rule of Civil Procedure (FRCP) 24(a), but the district court denied the motion as untimely. The sub-class appealed the denial.

The Ninth Circuit reversed, finding that the district court did not properly assess the timeliness of the motion. Ninth Circuit precedent requires that, when analyzing the timeliness of a motion to intervene, the important date is the time when the proposed interveners should have been aware that their interests were not adequately protected by the existing parties. It is not relevant when the litigation itself commenced, but rather the timing of the change in circumstances that created the need to intervene.

Although the litigation commenced in 2002, the settlement renegotiation that led to the closing of special education centers occurred in 2012 and started being implemented in 2013, and the court found that the sub-class moved to intervene as soon as was reasonably practicable following the change.