Fiduciary concerns spur new PBM models.(pharmacy benefit managers )

Lawsuits by members of private employee benefit plans against the four major pharmacy benefit managers - AdvancePCS, Caremark Rx, Express Scripts, and Medco Health Solutions - will further define, and perhaps redefine, PBM relationships with employers.

The core issue in the ongoing court cases is whether PBMs are fiduciaries under ERISA. By law, fiduciaries must act solely in the interests of plan members. Plaintiffs in ERISA lawsuits accuse PBMs of shirking fiduciary responsibility by - among other things - accepting hidden revenue streams from pharmaceutical manufactu