Question: who is the largest pbm?
Answer: Caremark (CVS Health) / Aetna: 30 percent.
Express Scripts: 23 percent.
OptumRx (UnitedHealth): 23 percent.
Humana Pharmacy Solutions: 7 percent.
MedImpact Healthcare Systems: 6 percent.
Prime Therapeutics: 6 percent.
All other PBMs + cash pay: 4 percent.