A lawsuit filed in the U.S. District Court in Sacramento accuses health insurance provider Cigna of using an algorithm, known as PxDx, to automatically review and deny hundreds of thousands of patient claims without individual evaluation by doctors. The lawsuit argues that these actions violate California state law, which requires insurers to conduct a thorough and fair investigation of each claim. By relying on the algorithm, Cigna can save money by denying claims and reduce labor costs by minimizing the time doctors spend reviewing each case.