Early identification of developmental delays and disabilities (DDs) is a key component of well-child visits. Recommendations for assessing children's development during these visits continue to evolve. For almost a century, developmental milestones have been used to identify children with atypical development. More recently, the American Academy of Pediatrics (AAP) has supported the medical home model and clinical guidelines to improve early identification of DDs in pediatric primary care. AAP's guidelines include a multilayered, continuous, collaborative, and family-centered approach to early identification. However, continued research, collaboration, and innovation across systems of care is needed to improve early identification of DDs.