Five facts about pharmacy benefit managers

NEW YORK, April 13 (Reuters) - Express Scripts Inc (ESRX.O: Quote, Profile, Research) said on Monday it will buy health insurer WellPoint Inc's (WLP.N: Quote, Profile, Research) NextRx prescription business for $4.68 billion. [ID:nBNG245941]

The deal would make Express Scripts the No. 2 U.S. pharmacy benefit manager in terms of prescription volume, trailing Medco Health Solutions Inc (MHS.N: Quote, Profile, Research).

Here are some facts about pharmacy benefit managers, or PBMs:

* Pharmacy benefit managers administer prescription drug benefits for employers and health plans and operate large mail-order pharmacies.

* PBMs specialize in driving use of lower-cost generic drugs, particularly through mail-delivery, which can help their clients lower their costs while boosting the PBMs' bottom lines.

* The four largest PBMs last year in terms of prescriptions were Medco (796 million), CVS Caremark (742 million) (CVS.N: Quote, Profile, Research), Express Scripts (506 million) and NextRx (268 million).

* Aside from WellPoint, other health insurers that operate PBMs include UnitedHealth Group (UNH.N: Quote, Profile, Research), Aetna (AET.N: Quote, Profile, Research) and Cigna (CI.N: Quote, Profile, Research).

* Analysts have speculated that health insurers would divest their PBM businesses because Wall Street has placed higher stock valuations on independent PBMs. (Reporting by Lewis Krauskopf, editing by Leslie Gevirtz)