The Federal Trade Commission is investigating the business practices of the six largest pharmacy benefit managers in the United States.

As part of its inquiry into the prescription drug middleman industry, the FTC has sent (or will be sending soon) orders to CVS Caremark, Express Scripts, Optum Rx, Humana, Prime Therapeutics, and MedImpact Healthcare Systems — requiring them to provide information and records regarding their business practices. The intent, according to agency officials, is to scrutinize the impact of vertically integrated pharmacy benefit managers (PBMs) on the access and affordability of prescription drugs. 

"Although many people have never heard of pharmacy benefit managers, these powerful middlemen have enormous influence over the U.S. prescription drug system," Federal Trade Commission Chair Lina M. Khan said in a statement. "This study will shine a light on these companies' practices and their impact on pharmacies, payers, doctors, and patients."