In Castellanos, et al. v. State of California, et al. (2024) 16 Cal.5th 588, the California Supreme Court upheld Proposition 22 against a key constitutional challenge, ruling that its workers' compensation provision (Bus. & Prof. Code § 7451) is valid. The court held that the Legislature's "plenary power" over workers' compensation is not exclusive and does not prevent the people from legislating on the same subject through the initiative process.

By limiting its holding to § 7451 and reserving judgment on other provisions, the court handed a major victory to app-based driver companies, ensuring Prop 22 survives while leaving the door open for future, narrower challenges.

In Olson et. al v. State of California (9th Cir. 2024) 104 F.4th 66, the Ninth Circuit en banc affirmed the dismissal of an Equal Protection challenge to A.B. 5, holding the law survives rational basis review. The court found that A.B. 5's complex framework and its distinctions between different types of referral services are rationally related to legitimate state interests, such as addressing worker misclassification.

This decision effectively ends the high-profile constitutional challenge by Uber and Postmates, confirming that the Legislature's line-drawing in the economic sphere is subject to a highly deferential standard.