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What Are the Developmental Milestones from 0 to 3, and What Does It Mean If My Child Isn't Doing One?

By the ParentingAI team · Last updated August 2026

The CDC's milestone checklists describe what most children — about 75% — can do by a given age. A missing milestone is not a verdict. It is a reason to have a conversation with your pediatrician, and to know that free developmental evaluation exists in every US state.

Here is the map, and here is who to talk to. That is the entire purpose of this article.

What changed about milestones in 2022?

They moved from describing the average child to describing most children — and that change was made specifically to stop parents being told to "wait and see."

This is the most important thing on the page, so it goes first.

Until February 2022, the CDC's milestone checklists were built around the 50th percentile — the age at which half of children had a given skill. The problem, in the CDC's own words: "With a milestone at 50%, half of all children would still reasonably be expected to have not yet achieved it." A checklist like that is almost impossible to act on. Half the children who "miss" a milestone are entirely on track, so families kept hearing wait, children develop differently, check back in six months. Some of those children needed support and did not get it for another year.

So the CDC and the American Academy of Pediatrics rebuilt the checklists around the 75th percentile — milestones that "about 75% or more of children would be expected to exhibit." The CDC states the goal directly: "This change is intended to reduce the 'wait and see' approach often taken when a child is missing an average age milestone."

The revision also added checklists at 15 months and 30 months, so there is now a checklist for every well-child visit from 2 months to 5 years.

What this means for how you read the lists below. These are not things your child should be doing. They are things most children can do by that age — which is exactly why a missing one is worth mentioning to your pediatrician rather than filing away. A missing milestone is information, not a diagnosis, and it does not tell you anything about your specific child on its own. That part is your pediatrician's job, with your child in the room.

What are the four areas of development?

The CDC organizes every checklist into the same four domains:

A child can be racing ahead in one domain and taking their time in another. That is ordinary. The domains are there so nothing gets overlooked, not so they can be compared against each other.

What can most babies do at 2 months?

Social/Emotional — Calms down when spoken to or picked up. Looks at your face. Seems happy to see you when you walk up. Smiles when you talk to or smile at them.

Language/Communication — Makes sounds other than crying. Reacts to loud sounds.

Cognitive — Watches you as you move. Looks at a toy for several seconds.

Movement/Physical — Holds head up when on tummy. Moves both arms and both legs. Opens hands briefly.

That first real social smile, somewhere around six to eight weeks, arrives after weeks of you talking to someone who mostly looks past you. It is worth the wait.

What can most babies do at 4 months?

Social/Emotional — Smiles on their own to get your attention. Chuckles (not yet a full laugh) when you try to make them laugh. Looks at you, moves, or makes sounds to get or keep your attention.

Language/Communication — Makes cooing sounds like "oooo" and "aahh." Makes sounds back when you talk to them. Turns head toward the sound of your voice.

Cognitive — Opens mouth when they see the breast or bottle if hungry. Looks at their hands with interest.

Movement/Physical — Holds head steady without support when you are holding them. Holds a toy when you put it in their hand. Uses their arm to swing at toys. Brings hands to mouth. Pushes up onto elbows or forearms when on tummy.

What can most babies do at 6 months?

Social/Emotional — Knows familiar people. Likes to look at self in a mirror. Laughs.

Language/Communication — Takes turns making sounds with you. Blows "raspberries." Makes squealing noises.

Cognitive — Puts things in their mouth to explore them. Reaches to grab a toy they want. Closes lips to show they do not want more food.

Movement/Physical — Rolls from tummy to back. Pushes up with straight arms when on tummy. Leans on hands to support themselves when sitting.

Note that "taking turns making sounds with you" sits under language. Before there are words, there is the rhythm of conversation — you make a sound, they make a sound, you wait. That back-and-forth is the foundation everything else is built on.

What can most babies do at 9 months?

Social/Emotional — Is shy, clingy, or fearful around strangers. Shows several facial expressions — happy, sad, angry, surprised. Looks when you call their name. Reacts when you leave, by looking, reaching for you, or crying. Smiles or laughs when you play peek-a-boo.

Language/Communication — Makes a lot of different sounds like "mamamama" and "bababababa." Lifts arms up to be picked up.

Cognitive — Looks for objects when dropped out of sight. Bangs two things together.

Movement/Physical — Gets to a sitting position by themselves. Moves things from one hand to the other. Uses fingers to rake food toward themselves. Sits without support.

Stranger anxiety is on the list as a milestone, not a problem. Your baby has worked out that you are specifically you. The clinginess is the achievement.

A note on this age: 9 months is one of the three ages — along with 18 and 30 months — where the CDC recommends your child receive a formal, standardized developmental screening at their well visit, not only the informal conversation. If nobody offers one, ask.

What can most children do at 12 months?

Social/Emotional — Plays games with you, like pat-a-cake.

Language/Communication — Waves bye-bye. Calls a parent "mama" or "dada" or another special name. Understands "no" — pauses briefly or stops when you say it.

Cognitive — Puts something in a container, like a block in a cup. Looks for things they see you hide, like a toy under a blanket.

Movement/Physical — Pulls up to stand. Walks holding on to furniture. Drinks from a cup without a lid, as you hold it. Picks things up between thumb and pointer finger.

Walking is famously absent from the 12-month list. It is not on the CDC's checklist until 18 months, which surprises nearly every parent whose relative has asked "is she walking yet?" at the first birthday party.

What can most children do at 15 months?

Social/Emotional — Copies other children while playing. Shows you an object they like. Claps when excited. Hugs a stuffed doll or other toy. Shows you affection with hugs, cuddles, or kisses.

Language/Communication — Tries to say one or two words besides "mama" or "dada." Looks at a familiar object when you name it. Follows directions given with both a gesture and words. Points to ask for something or to get help.

Cognitive — Tries to use things the right way — a phone, a cup, a book. Stacks at least two small objects, like blocks.

Movement/Physical — Takes a few steps on their own. Uses fingers to feed themselves some food.

This is one of the two checklists added in the 2022 revision. Before that, there was a fourteen-month gap between the 12-month and 18-month lists — a long stretch of a very eventful year with nothing to check against.

What can most children do at 18 months?

Social/Emotional — Moves away from you but looks to make sure you are close by. Points to show you something interesting. Puts hands out for you to wash them. Looks at a few pages in a book with you. Helps you dress them by pushing an arm through a sleeve or lifting a foot.

Language/Communication — Tries to say three or more words besides "mama" or "dada." Follows one-step directions without any gestures.

Cognitive — Copies you doing chores, like sweeping with a broom. Plays with toys in a simple way, like pushing a toy car.

Movement/Physical — Walks without holding on to anyone or anything. Scribbles. Drinks from a cup without a lid and may spill sometimes. Feeds themselves with their fingers. Tries to use a spoon. Climbs on and off a couch or chair without help.

A note on this age: 18 months is the second of the CDC's three recommended formal screening ages.

What can most children do at 24 months?

Social/Emotional — Notices when others are hurt or upset, like pausing or looking sad when someone is crying. Looks at your face to see how to react in a new situation.

Language/Communication — Points to things in a book when you ask. Says at least two words together, like "more milk." Points to at least two body parts when asked. Uses more gestures than waving and pointing — blowing a kiss, nodding yes.

Cognitive — Holds something in one hand while using the other. Tries to use switches, knobs, or buttons on a toy. Plays with more than one toy at the same time, like putting toy food on a toy plate.

Movement/Physical — Kicks a ball. Runs. Walks (not climbs) up a few stairs with or without help. Eats with a spoon.

"Says at least two words together" is the language milestone parents ask about most at this age. Note that it is two words together — not a vocabulary count, not clear pronunciation. "More milk" counts. "Mo mih" counts.

What can most children do at 30 months?

Social/Emotional — Plays next to other children and sometimes plays with them. Shows you what they can do by saying "Look at me!" Follows simple routines when told, like helping to pick up toys at clean-up time.

Language/Communication — Says about 50 words. Says two or more words together with one action word, like "doggie run." Names things in a book when you point and ask "What is this?" Says words like "I," "me," or "we."

Cognitive — Uses things to pretend, like feeding a block to a doll as if it were food. Shows simple problem-solving, like standing on a small stool to reach something. Follows two-step instructions. Shows they know at least one color.

Movement/Physical — Uses hands to twist things, like turning doorknobs or unscrewing lids. Takes some clothes off by themselves. Jumps off the ground with both feet. Turns book pages one at a time.

A note on this age: 30 months is the third recommended formal screening age, and this checklist was the other one added in 2022.

What can most children do at 36 months?

Social/Emotional — Calms down within 10 minutes after you leave, like at childcare drop-off. Notices other children and joins them to play.

Language/Communication — Talks with you in conversation using at least two back-and-forth exchanges. Asks "who," "what," "where," or "why" questions. Says what action is happening in a picture or book. Says their first name when asked. Talks well enough for others to understand, most of the time.

Cognitive — Draws a circle when you show them how. Avoids touching hot objects, like a stove, when you warn them.

Movement/Physical — Strings items together, like large beads or macaroni. Puts on some clothes by themselves. Uses a fork.

"Talks well enough for others to understand, most of the time" is doing a lot of work here — it means a stranger, not you. Parents become fluent in their own child's pronunciation without noticing, which is why the daycare teacher's read is genuinely useful information.

What should I do if my child isn't doing something on the list?

Two things, and they can happen in either order: tell your pediatrician, and call your state's early intervention program. Neither one requires the other.

Here is what each of those looks like.

1. Bring it to your pediatrician

The CDC's guidance is: "Talk to your child's doctor and share your concerns. Don't wait. Acting early can make a real difference!"

To make that conversation as useful as possible:

2. Call early intervention yourself — you do not need a referral

This is the part almost nobody knows, and it is the reason this article exists.

Every US state and territory runs a publicly funded early intervention program for children under 3. The CDC states it plainly: "Programs are available in every state and territory."

You can call them yourself. The CDC: "A doctor's referral is not necessary." And, more directly: "You do not need to wait for a doctor's referral or a medical diagnosis to make this call."

The evaluation is free. The CDC describes calling "your state's public early childhood system to request a free evaluation to find out if your child qualifies for intervention services," and notes these "publicly funded programs provide services for free or at reduced cost for any child who is eligible."

So if you are sitting with a worry and the next available appointment is in six weeks, you have a second door, and it is open now. Search "[your state] early intervention" or use the CDC's state contact list, linked below. You call, you describe what you have noticed, they arrange an evaluation.

Two things worth knowing before you dial. Not every child who is evaluated qualifies for services — and a "your child doesn't qualify" result is a genuinely good outcome, delivered by people who assess young children all day. And if your child does qualify, services are typically delivered in your home or childcare setting, built around your daily routines. It is far less clinical than it sounds.

Why does acting early matter?

Because the first three years are when the brain is building its foundational architecture, and support delivered during that window works with the grain of what is already happening.

There is also a practical reason. Waiting costs time that is difficult to get back, and the entire point of the CDC's 2022 revision was to remove the built-in reason to wait. The checklists were rewritten so that a missing milestone would mean something clear enough to act on.

None of which means urgency in the panicked sense. You have time to finish your coffee. You do not need to have this figured out today. Making a phone call this month rather than at the next birthday is the whole of what "acting early" asks of you.

The bottom line

These lists are a map, not a scorecard. They describe what most children can do by a given age — which means children who take a different route are common, and the checklist is designed to catch the ones worth a closer look, not to sort children into passing and failing.

If something on this page made you pause: write it down, tell your pediatrician, and know that a free evaluation is a phone call away and needs nobody's permission.

And if nothing did — put the phone down and go watch your kid bang two blocks together. That is on the 9-month list, and it is a genuinely impressive thing to be able to do.

Sources

Last medically reviewed: August 2026 Last updated: August 2026

This article is for informational purposes only and does not replace advice from your pediatrician. Always consult your healthcare provider for medical questions about your child.

Emergency numbers — United States 911 — medical emergency Poison Control: 1-800-222-1222 — 24/7, free, confidential

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