In 2011, the California Insurance Commissioner promulgated a regulation governing replacement cost estimates for homeowners insurance (Cal. Code Regs., tit. 10, §2695.183 [the Regulation]). After the trial court and intermediate court of appeal invalidated the Regulation,[1] this week the California Supreme Court reversed those decisions in a published decision, Association of California Insurance Companies v. Jones (Cal. Jan. 23, 2017) Case No. S226529. The Regulation was originally enacted in response to complaints from numerous homeowners who found that they were underinsured only after disaster completely destroyed their homes. In investigating these complaints, the Department of Insurance had found that the replacement cost coverage limit recommended by a number of insurers for their policyholders had understated what was actually necessary to…