The California Supreme Court settled an important insurance law issue in Montrose Chemical Corp. v. Superior Court, No. S244737 (Montrose III), adopting the rule of “vertical exhaustion” advocated by policyholders, over the rule of “horizontal exhaustion” advanced by insurers. The Court held that, to access otherwise available coverage under any excess insurance policy, policyholders need only exhaust the directly underlying excess policies for the same period (vertical exhaustion); they are not required to exhaust every lower level excess policy covering every policy period for which they had insurance (horizontal exhaustion). This is a significant win for California policyholders and many of Paladin Law Group’s clients.