This is a population-based system for the identification and early treatment of potentially devastating medical conditions. In the United States, this screening is mandated in every state, but the disorders included in the screening panels vary. A list of the screening tests provided by each state can be found on the National Newborn Screening and Genetics Resource Center website at http://genes-r-us.uthscsa.edu. An expert panel commissioned by the American College of Medical Genetics (ACMG) has recommended 29 conditions on newborn screening panels (Table 15–1). This chapter addresses selected disorders included in most state newborn screen panels, as well as special considerations related to discharge planning and follow-up. The American Academy of Pediatrics (AAP) has published newborn screening FACT sheets that address appropriate testing methods, follow-up, and diagnostic testing for all 29 disorders recommended by the ACMG.