Center for Disease Control and Prevention (2025)
Link: https://www.cdc.gov/ncbddd/actearly/milestones-app.html
Track your child’s milestones from age 2 months to 5 years with CDC’s easy-to-use illustrated checklists; get tips from CDC for encouraging your child’s development; and find out what to do if you are ever concerned about how your child is developing.