Make sure you check out NHeLP's latest publication, an issue brief on network adequacy in Medicaid managed care. In the issue brief, Abbi Coursolle explains the major Medicaid managed care requirements for network adequacy, with plenty of cites to statutes, regulations, and other resources. The issue brief also provides recommendations for advocates trying to improve network adequacy in Medicaid managed care systems.  

Network Adequacy in Medicaid Managed Care: Recommendations for Advocates (Sep. '13)