A Parent’s Guide · 12 to 36 Months

Early Signs of Autism in Toddlers.
What to actually watch for.

Plain-language red flags by age — written by BCBAs, not a checklist generator. If something feels off, you don’t have to wait until age 3 to find out. We test toddlers with no waitlist, and most families pay $0.

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18mo

Reliable signs visible

~1 wk

Typical eval wait

Most families pay

Earliest reliable age

Months

Trust your gut

You know your child best

Why this guide exists

Catching it early is the single biggest lever you have.

Autism can be reliably diagnosed by 18 months — but the average age of diagnosis in the U.S. is still over 4 years old. Those years matter. The toddler brain is doing more wiring per day than at any other point in life, and ABA therapy started before age 4 leads to dramatically better outcomes around communication, play, and self-help skills. Below is what BCBAs actually look for, broken down by age. If a few of these sound like your child, that’s a reason to call — not to panic.

Red Flags By Age

Milestones, and what it can mean when they don’t arrive.

Every child develops on their own timeline. The signs below are not a diagnosis — they’re the patterns clinicians take seriously enough to recommend an evaluation.

By 12 months

The social building-blocks

No back-and-forth babbling (“ba-ba-ba” with intonation)
Doesn’t respond to their name consistently
No pointing, waving, or reaching up to be picked up
Limited eye contact, especially during feeding or play
Doesn’t share attention — e.g. look at a toy, then up at you

By 18 months

Joint attention & first words

No single meaningful words (mama, dada, ball, more)
Doesn’t point at things to show interest (“Look, a dog!”)
No pretend play — no feeding a doll, no pushing a toy car with a “vroom”
Doesn’t follow your gaze or a point across the room
Prefers to play alone, even with caregivers nearby
Lining up toys, spinning wheels, or staring at fans/lights for long stretches

By 24 months

Two-word phrases & play

No 2-word phrases on their own (not echoing) — e.g. “more juice,” “daddy go”
Loss of words, social skills, or eye contact they previously had (regression)
Strong preference for routines — meltdowns when something is moved or changed
Unusual sensory responses: covering ears at normal sounds, refusing certain textures, mouthing non-food items late, seeking deep pressure
Repetitive body movements: hand-flapping, toe-walking, body-rocking, finger-twirling near the face

By 36 months

Conversation & pretend

Doesn’t use sentences of 3+ words, or speech is mostly echolalia (repeating phrases from videos)
Struggles with simple instructions like “put your cup on the table”
No interest in other children — doesn’t notice them, watch them, or try to join
Pretend play stays narrow or scripted — same scene replayed exactly the same way
Difficulty with transitions: leaving the park, ending screen time, changing clothes
Very intense, narrow interests (only one show, only one toy, only one food)

The signal clinicians weigh heaviest

Joint attention is the one to watch.

“Joint attention” is the moment your child looks at something interesting, then looks back at you to share it. It’s the foundation that language, conversation, and friendship are built on — and it’s the single most predictive early indicator of autism in toddlers. Three quick at-home checks:

The point test. Point at something interesting across the room (a dog out the window, a balloon). Does your toddler follow your finger with their eyes, then look back at your face? Or do they just stare at your hand — or ignore it?
The show test. Hold up a toy and say “look!” Does your toddler glance at the toy, then up at you to check your reaction? That tiny back-and-forth glance is joint attention.
The bring test. Do they bring you a book, a snack, or a broken toy — not just to fix it, but to show you? Or do they take your hand and use it like a tool, without looking at your face?

One missed cue isn’t diagnostic. A consistent pattern, especially past 18 months, is a strong reason to schedule an evaluation.

If a few of these sound familiar

You don’t have to wait and see.

Most pediatricians refer for an evaluation when the toddler’s 18-month or 24-month checkup raises concerns — but you can self-refer too. Our evaluations are usually scheduled within a week, and most families pay $0 through insurance or Medicaid.

See How Testing Works Call (888) 989-5011

If you’re seeing the signs

Here’s exactly what to do this week.

Write down what you’re seeing.

A short list — behaviors, ages they started, frequency. Two short videos on your phone (one of play, one of mealtime) are worth a thousand words to a clinician.

Talk to your pediatrician.

Bring your list to the next well-child visit (or call sooner). Ask for an M-CHAT-R screening if your toddler is 16–30 months. A pediatrician referral can speed up insurance.

Don’t wait on a referral.

You can also self-refer directly to an evaluator. We don’t require a pediatrician’s note. Bring your insurance card and we handle the rest.

Schedule the evaluation.

An evaluation is a few hours of structured play and parent interview — not a hospital visit. Your toddler doesn’t need to “perform.” They just need to be themselves.

Keep playing & talking.

Get on the floor. Narrate everything you do. Pause and wait — give them time to respond. None of this changes the diagnosis, but all of it helps their brain.

Lean on people who know.

A diagnosis is a doorway, not a verdict. Our BCBAs will walk you through what comes next — whether that’s ABA therapy, speech, OT, or just regular check-ins.

Frequently Asked

Honest answers to what parents actually ask us.

Can autism really be diagnosed before age 3?

Yes. A reliable diagnosis can be made as early as 18 months, and even earlier in some cases. The earlier you know, the earlier your child can start the kind of supports — ABA, speech, OT — that take advantage of the brain’s peak plasticity window. Don’t let anyone tell you to “wait until they’re 4” if you see consistent signs.

My toddler makes eye contact with me. Does that rule out autism?

No. Plenty of autistic toddlers make warm eye contact with parents and primary caregivers, but show different patterns with strangers, in groups, or when they want something. Eye contact is one of many signals — not a pass/fail test. The bigger picture is joint attention, response to name, gesture, and pretend play.

Is hand-flapping or toe-walking always autism?

No. Lots of typically developing toddlers flap when excited or toe-walk for a few months as they learn to balance. These become more concerning when they are frequent, hard to interrupt, paired with other signs (language delay, no joint attention), or persist past age 2 to 3. The pattern matters more than any one behavior.

What actually happens at an autism evaluation?

A trained clinician spends a few hours with you and your child, using a structured play-based assessment (typically the ADOS-2 for toddlers) plus a detailed parent interview. There are no needles, no scans, no scary equipment — just toys, conversation, and a clinician watching how your child engages. You leave with a written report and a clear next step.

How much does an evaluation cost?

For most families: $0. We accept most major commercial insurance plans and Medicaid, and we verify your specific coverage on the first phone call so there are no surprises. If a family is uninsured or out-of-network, we’ll explain the self-pay rate up front — no hidden fees.

What parents tell us

“Very professional staff who are very knowledgeable about Autism. Highly recommend to any parent who wants excellent therapy for their child.”

— D. M., Parent

Ready when you are

Clear answers, real direction.

Schedule an evaluation, or just call us and ask questions. There’s no pressure, no script, and no waitlist — only honest answers from BCBAs who do this every day.