The Product Development Team (PD) in the US Environmental Protection Agency's ENERGY STAR Labeling Program fuels the long-term market transformation process by delivering new specifications. PD's goal is to expand the reach and visibility of ENERGY STAR as well as the market for new energy-efficient products. As of 2002, PD has launched nine new ENERGY STAR specifications and continues to evaluate new program opportunities. To evaluate the ENERGY STAR potential for a diverse group of products, PD prepared a framework for developing new and updating existing specifications that rationalizes new product opportunities and draws upon the expertise and resources of other stakeholders. Manufacturers and stakeholders have a vested interest in understanding how ENERGY STAR products are selected for labeling. In this article, we explore in depth PD's process and also provide two case studies that illustrate the application of PD's framework. After 3 years of implementation. several lessons learned have emerged. Manufacturers are increasingly inquiring as to why a product is/is not labeled. Careful application of the framework allows PD to justify program decisions. PD increasingly recognizes that each industry has unique market and product characteristics that can require reconciliation with the guidelines of the ENERGY STAR program. Careful application of the framework identifies where reconciliation is needed to preserve the program integrity and justify decisions. Finally, to date, the application of the framework has enabled PD to navigate through complex product issues and make consistent specification development decisions. (c) 2004 Elsevier Ltd. All rights reserved.