The public will have a chance to see what until now has been, mostly, understood only by managed care insiders: how a prescription drug winds up on a formulary.

Express Scripts, one of the largest pharmacy benefit managers, will soon begin to post conclusions of its pharmacy and therapeutics committee on its web site.

Express Scripts wants to give the public and health care professionals an idea of the thought process and logic involved when the P&T committee considers whether to add a drug to the formulary.

The PBM will not post minutes of P&T meetings, but will summarize discussions about products, whether and under what circumstances they should be covered, and at what out-of-pocket cost to the member.

PBMs are just now beginning to gain public attention. Reports about how PBMs control the pharmacy benefit gained coverage in the mainstream press last year, triggering some public resentment.