This article describes the background, development, and initial implementation of new procedures for the systematic review of key issues in newborn screening. Building on the work of other systematic review efforts, the Evidence Review Group described here has aimed to develop consistent and transparent strategies for evidence review. This process has helped to strengthen a complex analysis and decision system by providing balanced evidence, taking into account available high-quality data, expert opinion, and other levels of evidence, in a transparent manner. The methods developed and the identification of areas of missing data may also help investigators begin to standardize the clinical and laboratory data they collect pertaining to the newborn screening and diagnosis of rare disorders and their outcomes and focus future research efforts in the most needed areas.