From 1 January 1999, all requests by pharmaceutical manufacturers and others to Blue Cross and Blue Shield (BCBS) of Colorado and Nevada for the listing of new pharmaceutical products or any proposed change to the formulary status of an existing product must be accompanied by a submission which meets the informational and analytical standards set out in the BCBS Guidelines for Formulary Submissions for Pharmaceutical Product Evaluation. These submission requirements relate both to the anticipated therapeutic impact of a new product and to claims made as to its anticipated pharmacoeconomic impact. The guidelines have been developed because BCBS is concerned that decisions to admit a drug to formulary have been based in the past on incomplete information. In order to rectify this situation (and to meet quality control objectives), it has been decided that all submissions to BCBS should meet a common information standard that describes both the characteristics of the product and its expected impact in a disease or therapeutic area. Unlike guidelines that have been introduced in countries such as Australia and the Canadian Province of Ontario, these guidelines take an explicit systems approach to the case a manufacturer must make before a product is considered for formulary listing. While the notion of systems impact requirements is not new, this is the first time that a managed healthcare system in the US has adopted this explicit perspective and notified manufacturers that traditional pharmacoeconomic evaluations may not meet the information needs of drug purchasers. The purpose of this paper is to describe the BCBS formulary guidelines and to demonstrate how manufacturers are expected to meet the information needs of a systems impact perspective in submissions to the pharmacy and therapeutics committee.