Child Development Milestones: Ages 0–5 Years
Developmental milestones are skills that most children achieve by a certain age. They're not a competition — every child develops at their own pace. But milestones matter because they help pediatricians identify children who may benefit from early intervention, which is most effective when started early. This guide uses the updated CDC/AAP milestone checklists.
The CDC updated its developmental milestone checklists in 2022 to reflect what MOST children (75%) can do by a given age, rather than the earliest age a child might achieve a skill. This change was made to improve early identification of developmental delays.
2 Months
- Social/Emotional: Calms down when spoken to or picked up; smiles when you talk or smile at them
- Language: Makes sounds other than crying; reacts to loud sounds
- Cognitive: Watches you as you move; looks at a toy for several seconds
- Motor: Holds head up when on tummy; moves both arms and legs
4 Months
- Social/Emotional: Smiles on their own to get your attention; chuckles
- Language: Makes sounds like "oooo" and "ahhh"; makes sounds back when you talk
- Cognitive: Opens mouth in response to breast or bottle; looks at hands with interest
- Motor: Holds head steady without support; pushes up on elbows/forearms during tummy time
6 Months
- Social/Emotional: Knows familiar people; likes to look at self in mirror
- Language: Takes turns making sounds with you; blows "raspberries"
- Cognitive: Puts things in mouth to explore; reaches to grab a toy
- Motor: Rolls from tummy to back; pushes up with straight arms during tummy time
9 Months
- Social/Emotional: Is shy, clingy, or fearful around strangers; shows several facial expressions
- Language: Makes different sounds like "mamamama" and "babababa"
- Cognitive: Looks for objects when dropped out of sight; bangs two things together
- Motor: Gets to a sitting position by self; pulls to stand; picks up small objects with thumb and index finger
12 Months
- Social/Emotional: Plays games with you like pat-a-cake
- Language: Waves "bye-bye"; calls a parent "mama" or "dada" or another special name; understands "no"
- Cognitive: Puts something in a container; looks for things hidden out of sight
- Motor: Pulls up to stand; walks holding on to furniture; drinks from a cup without a lid with help
18 Months
- Language: Tries to say 3+ words besides "mama" or "dada"; follows 1-step directions
- Cognitive: Copies you doing chores; plays with toys in a simple way
- Motor: Walks without holding on; scribbles; drinks from a cup without a lid
2 Years
- Language: Says 50+ words; says 2-word phrases; uses more words than gestures
- Cognitive: Holds something in one hand while using the other; tries to use switches and buttons
- Motor: Runs; kicks a ball; climbs on and off furniture without help
3 Years
- Language: Talks with you in conversation using 2+ back-and-forth exchanges; asks "who," "what," "where," or "why" questions
- Cognitive: Draws a circle when you show them; avoids touching hot objects
- Motor: Strings items together; puts on some clothes by self; uses a fork
When to Talk to Your Pediatrician
Contact your pediatrician if your child:
- Loses skills they once had at any age
- Doesn't make eye contact by 2 months
- Doesn't respond to their name by 9 months
- Doesn't say any words by 12 months
- Doesn't say 2-word phrases by 24 months
- Shows any of the "red flags" on the M-CHAT screening tool for autism
Pro Tip
Early intervention services (available through your state's Part C program for children under 3) are free and can make a significant difference. You don't need a diagnosis to access services — a developmental delay is sufficient.