An autism milestone checklist lists the communication, social, play, and movement skills most children show by certain ages, so parents can spot gaps early. Missing one milestone rarely means autism. But several missed social and communication milestones, or any loss of a skill your child once had, is a clear reason to request a developmental screening.

The CDC’s “Learn the Signs. Act Early.” checklists, updated in 2022, list skills that most children (at least 75%) can do by each age. That means a missed item is a signal to look closer, not a diagnosis. The American Academy of Pediatrics also recommends autism-specific screening at 18 and 24 months, on top of regular developmental monitoring.

This guide pulls the milestones that matter most for autism into one age-by-age checklist, explains which ones are the strongest early indicators, and walks you through what to do with what you find. It is a parent guide, not a diagnostic tool. Only a licensed clinician can diagnose autism.

What Is a Developmental Milestone?

A developmental milestone is a skill most children develop within a typical age range, such as waving goodbye, saying a first word, or taking turns in a game. Milestones are grouped into four areas: social and emotional, language and communication, cognitive (learning and play), and movement. Autism mostly shows up in the first two areas, which is why social and communication milestones get the closest attention.

Milestones are a range, not a deadline. Many healthy children reach some skills a little early or late. What matters is the overall pattern across areas and whether your child keeps gaining new skills over time.

How to Use This Checklist

• Look for patterns, not single items. One missed skill is common. Several missed skills in social communication deserve a conversation with your pediatrician.
• Compare against the checklist, not against cousins or neighbors. Every child’s pace is different, and informal comparisons are unreliable.
• Watch across settings. Note whether a skill shows up at home, at daycare, and with different people.
• Write down specific examples, such as “does not turn when I call his name, even in a quiet room.” Concrete notes make appointments far more productive.
• Track skill loss separately. Losing a word, gesture, or social skill is always worth raising right away, regardless of age.

Autism Milestone Checklist by Age

The table below summarizes key skills at each age. It is reworded and condensed from the CDC’s milestone checklists. For the complete lists, use the free CDC Milestone Tracker.

Age	Social and emotional	Language and communication	Play and learning
12 months	Enjoys back-and-forth games like peekaboo or pat-a-cake	Waves bye-bye; uses a special name for a parent; pauses when told “no”; babbles with varied sounds	Puts objects into a container; looks for a toy you hide; picks up small items with thumb and finger
15 months	Shows you objects to share interest; copies simple actions	Tries one or two words besides “mama” and “dada”; points to ask for something; follows a simple direction paired with a gesture	Uses objects the right way (cup, phone, book); stacks two small objects
18 months	Points to show you something interesting; checks that you are nearby while exploring; copies you doing chores	Says three or more words besides “mama” and “dada”; follows a one-step direction without gestures	Plays with toys in simple, functional ways (pushing a car); looks at book pages with you
24 months	Notices when others are upset; looks at your face to decide how to react in new situations	Puts two words together; points to body parts or pictures when asked; uses gestures beyond waving and pointing (blowing a kiss, nodding)	Plays with more than one toy at a time; begins simple pretend play like feeding a doll
30 months	Plays beside other children and sometimes with them; says “look at me!” to show what she can do	Uses about 50 words; combines a noun and a verb; uses “I,” “me,” and “we”; names things in a book	Pretends with objects; follows routines when told, like clean-up time; solves simple problems
3 years	Notices and joins other children’s play; settles within about ten minutes after a caregiver leaves	Holds a short conversation with back-and-forth turns; asks who, what, where, and why; speech is mostly understood by others	Draws a circle; plays make-believe with dolls or animals; builds with blocks
4 years	Pretends to be someone else in play; comforts others who are hurt; adjusts behavior to the setting	Speaks in sentences of four or more words; talks about something that happened during the day; answers simple questions	Names some colors; retells part of a familiar story or song; draws a person with several body parts
5 years	Follows rules and takes turns in games; likes to help; sings, dances, or performs for others	Keeps a conversation going for several turns; tells a simple story with at least two events; answers questions about a book	Counts to ten; writes some letters of their name; stays with an activity for five to ten minutes

 

Source basis: CDC “Learn the Signs. Act Early.” milestone checklists (2022 update), summarized in our own words.

The Milestones That Matter Most for Autism

Some milestones are stronger early indicators of autism than others, because they reflect social communication, the core area where autism shows up. If you only have time to watch for a handful of skills, make it these:

Milestone	What it looks like	Why it matters	Typical timing
Response to name	Turns or looks when called, most of the time	Reflects social attention and awareness of other people	By about 9 to 12 months
Joint attention	Looks at an object, then at you, then back at the object	The foundation of shared experience and language learning	Developing from 9 to 15 months
Pointing to share	Points to show you something, not only to ask for it	Shows a desire to share interest with others	By about 12 to 18 months
Gestures	Waves, claps, shakes head, reaches to be picked up	Early communication before words	By about 12 months
Imitation	Copies your actions and sounds	How children learn most early skills	From about 9 months onward
Pretend play	Feeds a doll, “drives” a car, talks on a toy phone	Reflects flexible thinking and social imagination	Emerging from 18 to 24 months
Back-and-forth communication	Takes turns with sounds, words, or actions	The building block of conversation	Throughout toddlerhood

 

For a deeper look at the specific red flags at 12, 18, 24, and 36 months, see our guide to signs of autism in toddlers.

Red Flags to Raise With Your Doctor Sooner

The following are reasons to request a developmental screening promptly rather than waiting for the next routine visit:

• No babbling, pointing, or other gestures by 12 months
• No single words by 16 months
• No meaningful two-word phrases by 24 months
• Rarely responding to their name, or seeming not to hear you while hearing is otherwise normal
• Little interest in sharing enjoyment with you, such as not showing you toys or pointing out interesting things
• Any loss of previously gained words, gestures, eye contact, or social interest at any age

Missing Milestones vs. Autism: Is It Always Autism?

No. Missing milestones can have many causes, and autism is only one. Other common explanations include hearing loss, an isolated speech or language delay, global developmental delay, ADHD, anxiety, and simple variation in typical development. This is why a thorough evaluation always looks at the whole child, and why a hearing test is a standard early step.

Meeting every milestone on time does not rule out autism, either. Children with strong language skills, and many girls, can have subtler differences that checklists miss. If your instincts say something is different, trust that and ask for an evaluation.

Skill Loss (Regression): The Sign Not to Wait On

A child who was saying words, waving, or making eye contact and then stops is showing regression. It most often appears between about 15 and 24 months. Regression is never a “wait and see” situation. Contact your pediatrician right away, describe exactly what was lost and when, and ask for a developmental evaluation.

What to Do If Your Child Is Missing Milestones

Step 1: Call your pediatrician and request a developmental screening. Ask specifically for an autism screening tool such as the M-CHAT-R/F, a 20-question parent questionnaire designed for toddlers between roughly 16 and 30 months.

Step 2: Request a hearing check. Hearing problems can mimic or accompany communication delays, and ruling them out is a routine part of the process.

Step 3: Contact early intervention. In North Carolina, children under 3 can be referred to the NC Infant-Toddler Program for a free developmental evaluation. Children 3 and older can be evaluated through the local public school system. You do not need a diagnosis to start either process.

Step 4: Book a comprehensive diagnostic evaluation. A licensed psychologist can use standardized, play-based tools to determine whether your child meets criteria for autism. Learn more about autism diagnostic evaluations at Little Hearts ABA.

Step 5: Keep notes and keep monitoring. Continue tracking skills while you wait. Notes about progress, new skills, and ongoing concerns help every professional you see.

Common Mistakes Parents Make With Milestone Checklists

Mistake 1: Waiting for the next scheduled visit. If you see a pattern of concerns or any skill loss, call now.

Mistake 2: Treating a checklist as a diagnosis. Checklists point to what deserves a closer look. They cannot confirm or rule out autism.

Mistake 3: Being reassured by “he’ll catch up.” Some children do. But early evaluation costs little, and if support is needed, earlier is better.

Mistake 4: Focusing only on speech. Gestures, shared attention, and play often tell you more about early social communication than the number of words.

Mistake 5: Using the wrong age checklist. Use your child’s actual age, and ask your pediatrician about age adjustments for babies born early.

Expert Recommendations

• Use the free CDC Milestone Tracker app or printed checklists and review them every few months.
• Bring your notes, and any short videos of behaviors you are worried about, to your pediatrician.
• Request autism-specific screening at the 18- and 24-month well visits if it is not offered automatically.
• Start early intervention services while evaluation is in progress. Waiting for a diagnosis is not required.
• Choose an evaluation provider that can see your child quickly. Long waitlists delay support when early access matters most.

Statistics Every Parent Should Know

• About 1 in 31 children (3.2%) in the U.S. is identified with autism spectrum disorder by age 8, according to the CDC’s ADDM Network (2022 data, published April 2025).
• Autism can be reliably diagnosed by 18 to 24 months with standardized tools, yet many children are not diagnosed until years later.
• The AAP recommends autism-specific screening for all children at 18 and 24 months, in addition to ongoing developmental surveillance at every well visit.
• Since 2022, CDC milestone checklists list skills that at least 75% of children can do by each age, which makes a missed milestone a more meaningful signal than under older versions.

Sources: CDC ADDM Network; CDC “Learn the Signs. Act Early.”; American Academy of Pediatrics.

Frequently Asked Questions

At what age can autism be diagnosed?

Autism can be reliably diagnosed as early as 18 to 24 months using standardized evaluation tools. Screening can begin even earlier, and concerns at 12 months are worth raising with a pediatrician.

Which milestones do autistic toddlers most commonly miss?

Social communication milestones are the most common: responding to their name, pointing to share interest, using gestures, imitating others, and pretend play. Language delays are also common but are not present in every autistic child.

Can a child meet all milestones and still be autistic?

Yes. Checklists are broad, and autism can be subtle, particularly in children with strong language skills and in girls who learn to mask social differences. If you have ongoing concerns, ask for an evaluation even if your child is meeting most milestones.

Is a late talker autistic?

Not necessarily. Many late talkers have an isolated speech or language delay. Autism is more likely when a speech delay appears alongside differences in eye contact, gestures, shared attention, play, or response to name.

What if my child reaches milestones late but is now catching up?

That can be normal variation. It is still worth mentioning to your pediatrician, because a pattern of late milestones across areas, or unevenness that persists, may deserve monitoring.

What is the M-CHAT-R/F?

The Modified Checklist for Autism in Toddlers, Revised with Follow-Up, is a 20-question parent questionnaire used to screen toddlers roughly 16 to 30 months old. A positive result means a closer evaluation is recommended, not that your child has autism.

Do I need a diagnosis to start early intervention?

No. Early intervention services for children under 3 are based on developmental delay or risk, not a formal autism diagnosis. You can begin the referral process as soon as you have concerns.

How do I track milestones at home?

The CDC offers a free Milestone Tracker app and printable checklists for ages 2 months through 5 years. Review them every few months, and record specific examples of skills your child has or has not shown.

Do autistic children develop skills in a different order?

Often, yes. Many autistic children develop skills unevenly, being advanced in some areas such as memory or letters while delayed in others such as social communication. This uneven profile is one reason a full evaluation looks at many areas.

Who should I call first if I am worried?

Start with your child’s pediatrician and request a developmental screening. You can also contact your state’s early intervention program directly, or a diagnostic evaluation provider, without waiting for a referral in many cases.

Conclusion

A milestone checklist will not tell you whether your child is autistic, but it gives you a clear, practical way to notice what deserves attention and to describe your concerns with confidence. The earlier a pattern is spotted, the earlier your child can get the right support.

If you are noticing missed milestones and want clear answers, the next step is a comprehensive evaluation, not more waiting. Little Hearts ABA provides autism diagnostic evaluations for children 18 months to 18 years, with insurance verification handled for you and a typical turnaround of two to four weeks. Contact our team today to schedule your child’s evaluation.