Medical Insurance: a Revenue Cycle Process Approach by 
Medical Coding Workbook for Physician Practices and Facilities by Ch 8 "Private Payers / ACA Plans"
This chapter describes the broad groups of private payers, including BlueCross BlueShield, & the types of private plans, along with describing ACA plans. It also covers participation contracts & managing capitation contracts.
Ch 9 "Medicare"
This chapter covers Medicare eligibility, enrollment, different plans, reimbursement methodologies, and completion of claims.
Health Care Finance and the Mechanics of Insurance and Reimbursement by 
Fundamentals of Coding, Payment, and Documentation by 