UnitedHealth Group last week said it has...

...entered an agreement to acquire Diplomat Pharmacy, Inc., a specialty pharmacy benefits manager that has faced financial difficulties in recent years, for $300 million. United's health insurance unit is currently the largest insurer in the U.S., enrolling 44,612,324 members, or 13.7% of all medical lives. The company handles its members drug benefits through its in-house PBM, OptumRx, the unit that will acquire Diplomat pending regulatory approval.

From AIS’s Directory of Health Plans