In the early 1960s, the newborn screening (NBS) program in the United States began with testing for phenylketonuria. Since that time, the NBS program has greatly expanded the number of disorders tested in all newborns. This article reviews the importance of NBS from a public health perspective as well as in the clinical setting to detect, diagnose, and manage conditions early. Current practices vary across the United States as well as internationally. While there have been several advancements in NBS over the past several decades, multiple challenges and limitations remain. Some of these challenges include false-positive and false-negative results, the ethical dilemma of consent, and optimal timing of NBS in the neonatal intensive care unit. Future directions of NBS, both nationally and internationally, include the implementation of next-generation sequencing testing and artificial intelligence.