The United States Government Accountability Office (GAO) has issued a report on state and federal oversight of private health insurance provider networks.  GAO found that there was wide variation in how states and the federal government monitored the adequacy of private health insurance provider networks and that interrelated factors contributed to inadequate networks, such as provider shortages, challenges in contracting with providers, and geography.  To read the GAO report on state and federal oversight of private health insurance provider networks, use the first link below.  To read GAO highlights of the report on state and federal oversight of private health insurance provider networks, use the second link below.
https://www.gao.gov/assets/gao-23-105642.pdf  (GAO report on state and federal oversight of private health insurance provider networks)
https://www.gao.gov/assets/gao-23-105642-highlights.pdf  (GAO highlights on state and federal oversight of private health insurance provider networks)