In Truck Ins. Exch. v. Kaiser Cement, 321 Cal. Rptr. 3d 761, 549 P.3d 781 (2024), the California Supreme Court answered the question left open by Montrose Chem. Corp. v. Superior Ct., 9 Cal. 5th 215 (2020) (Montrose III): for a continuous injury or damage spanning multiple policy periods, must an insured exhaust all implicated primary policies spanning the entire period of injury or damage prior to accessing any excess policy during that period.
