Pharmacy Benefits Manager Accountability Act This bill establishes reporting requirements for pharmacy benefit managers (PBMs) with respect to services provided to health insurance plans. First, PBMs must report annually to the plan sponsor certain information about the PBM's services, including the amount of prescription drug copayment assistance funded by drug manufacturers, a list of covered drugs billed under the plan during the reporting period, and the total gross and net spending by the health plan on prescription drugs during the reporting period. PBMs also must submit specified elements of the report (e.g., the total gross spending on prescription drugs) to the Government Accountability Office (GAO). The report must comply with the privacy requirements under the Health Insurance Portability and Accountability Act of 1996. The bill establishes civil penalties for violations of these requirements and provides for enforcement by the appropriate agencies. GAO must report on the pharmacy networks of plans or PBMs, including whether such networks under common ownership with the plans or PBMs are designed to encourage plan enrollees to use network pharmacies over other pharmacies.