Sure. In many parts of the United States, regional hospital systems have captured their local markets through consolidation and exploitation of their non-profit status. They then offer their own health insurance plans to provide access their own hospital systems, sometimes even denying access to other insurance plans. So when these insurance plans spend on patient care, they are, in effect, paying themselves at rates they have strong influence over.
For example, in western Pennsylvania, there is UPMC. According to court documents, UPMC acquired 28 competitors between 1996 and 2018. According to the Pennsylvania Attorney General's office, in 2011 UPMC announced it would stop accepting patients insured by its competitor, Highmark. This prompted the PA government to "enter into consent decrees with both UPMC and Highmark to protect access to care." Which, again according to the Pennsylvania Attorney General's office, UPMC continued to violate. This has lead to, among other things, a recent antitrust lawsuit supported by the US Justice Dept. [1] [2]
[1] https://www.attorneygeneral.gov/upmc/
[2] https://www.wesa.fm/health-science-tech/2024-10-03/justice-d...