A bipartisan group of U.S. senators wrote a letter to the Federal Trade Commission in January requesting an update on its ongoing investigation of pharmacy benefit managers.

"We support the FTC's issuance of a Section 6(b) order and conducting a timely study of PBMs' business practices," said the letter from Sen. Chuck Grassley, R-Iowa, Sen. Maria Cantwell, D-Wash., and 12 colleagues. "With the FTC's inquiry reaching its year-and-a-half mark, we urge the FTC to complete the study without delay. In the interim, we believe it is important to know the status of the study and therefore ask the FTC to issue a progress report."

The FTC launched its inquiry in June 2022 after Grassley had pressed the commission for years to review PBMs' role in determining prices for prescriptions such as insulin. As part of its inquiry, the FTC sent orders to CVS Caremark, Express Scripts, Optum Rx, Humana, Prime Therapeutic and MedImpact Healthcare Systems requiring them to provide information and records regarding their business practices. The intent, according to agency officials, was to scrutinize the impact of vertically integrated PBMs on the access and affordability of prescription drugs.