ProPublica: Cigna's PxDx system let its doctors reject claims in bulk without opening patient files
What happenedA ProPublica investigation published in March 2023 reported that Cigna used an automated system called PxDx. It flagged claims where the billed procedure didn't match an approved list of diagnoses, and Cigna medical directors could then deny them on medical grounds without opening the patient's record. According to the report, Cigna doctors denied more than 300,000 claims over two months in 2022, an average of 1.2 seconds per claim. A former Cigna doctor was quoted: 'We literally click and submit... It takes all of 10 seconds to do 50 at a time.' Patients were left with unexpected bills. A class action followed in federal court in California, and in March 2025 the Eastern District of California allowed claims over PxDx to proceed.
Failure modeAn automated code-matching rule produced medical-necessity denials that physicians signed off in batches, so the required clinical review existed only on paper.
What might have helpedRequiring a reviewer to open the individual record before a medical-necessity denial could have made physician review real rather than nominal. Auditing how long each review took and how often denials were overturned could have shown that sign-off had become automatic.
Partly mitigated Since thenCalifornia's Physicians Make Decisions Act (SB 1120) took effect on 1 January 2025. It bars health plans and disability insurers from using AI, algorithms or other software to deny, delay or modify care on medical-necessity grounds; a licensed physician or other qualified professional must make that decision. The tools must also be applied fairly and equitably and are open to audit by the DMHC and the Department of Insurance.
Still openThe law covers only plans regulated by California. Self-funded employer plans under ERISA and patients in other states are outside it. It requires a professional to make the decision but does not say how long a review must take, so a 1.2-second click-through review is not expressly ruled out. Cigna denies that PxDx is an algorithm, and the class action was still going on as of September 2026 with no settlement found.
LessonThe case suggests that simply having a physician sign off doesn't make the review meaningful. The California law requires a professional to decide but leaves open how closely they must actually look at each case, which may be where the next dispute arises.
Sources: sd13.senate.ca.gov · fenwick.com · nfp.com