A developmental milestone is a skill that most children reach by a certain age, such as smiling, sitting, waving or walking. In the CDC's checklists, each milestone is set at the age by which at least 75% of children are expected to show it.
Examples of milestones
These examples come from the CDC's milestone checklists:
| By age | Example milestone |
|---|---|
| 2 months | Smiles when you talk to or smile at them |
| 4 months | Holds head steady without support when held |
| 6 months | Rolls from tummy to back |
| 9 months | Sits without support; makes sounds like "mamamama" |
| 1 year | Pulls up to stand; waves "bye-bye" |
| 18 months | Walks without holding on to anything |
| 2 years | Says at least two words together, like "more milk" |
What you can do
- Use a milestone checklist at each age to track your child's progress.
- Share the checklist with your doctor at check-ups.
When to talk to your doctor
Talk to your doctor if your child has not reached the milestones for their age, or if they lose skills they once had. Do not wait to see if they catch up.
Frequently asked questions
Children develop at different speeds; your doctor will look at the overall picture.