Some detailed HMO history here, followed by lots of insider detail (parts 2 and 3) on how HMOs are using AI to dominate the healthcare system.
"Hospitals saw, in some cases, a doubling of claims denials or “repricing” in just a 12 to 18-month period after 2016 based on these automated” reviews. This surge of machine-driven denials played a major role in the mysterious 39% plummet in hospital operating earnings"