Developmental milestones are behaviors and skills that most children demonstrate at a given age. It’s important to note that all children develop differently. Milestone checklists provide examples of typical development progress at that age.

CDC’s Learn the Signs, Act Early (LTSAE) provides free, family-friendly, high-quality, and research-based resources to engage families and providers in monitoring children’s developmental milestones from ages 2 months through 5 years. These resources can help families learn the signs of child development and encourage them to act early and get help for their child when they have questions or concerns.

LTSAE encourages families to monitor and celebrate milestones, share progress with their child’s doctor at every well-visit and with other care providers, and act early on any concerns. CDC’s milestone checklists include milestones most children (75% or more) are expected to reach by a given age. This is intended to avoid a “wait and see” approach; any missed milestone or concern should prompt discussion or action.

Click on the age of your child to see the milestones from Learn the Signs. Act Early, an initiative of the Centers for Disease Control and Prevention:

• Milestones by 2 Months
• Milestones by 4 Months
• Milestones by 6 Months
• Milestones by 9 Months
• Milestones by 1 Year
• Milestones by 15 Months
• Milestones by 18 Months
• Milestones by 2 Years
• Milestones by 30 Months
• Milestones by 3 Years
• Milestones by 4 Years
• Milestones by 5 Years

Download the entire set of Milestone Checklists. Available in English, Spanish, Chinese, Tagalog, Vietnamese, and several other languages. Remember, the checklists provide general guidelines; they are not a substitute for a developmental screening.

You can download the Milestone Tracker mobile app for iOS and Android devices (Spanish language version will be available in fall 2018) and view the Milestones in Action photo and video library.

Interested in learning more about early child development? Check out our article to learn the top 5 things you should know about your young child’s development and when to consult with a professional about any concerns you may have.

Source: Centers for Disease Control and Prevention |Developmental Milestones, https://www.cdc.gov/act-early | Public domain. Last reviewed January 2026.