Signs of autism in babies (6-12 months)
Some signs of autism can show in the first year. Here is what researchers say to watch for in babies, and why acting early in Colorado costs nothing.
Some signs appear in infancy. The earlier you start, the more help is available.
In babies, the early signs of autism are subtle: little eye contact, few shared smiles, and not turning to their name by 9 months. A baby might also not reach up to be picked up, the way most babies do. Autism can sometimes be detected by 18 months, and some signs show even earlier. A baby is too young for a firm diagnosis, but not too young to start a free evaluation in Colorado. At Budding Futures ABA, we help Colorado families know when an infant's behavior is worth checking.
On this page
Signs of autism in babies by age
Babies vary a lot, so one missed milestone is rarely a worry. A pattern of several, especially around 9-12 months, is worth raising with your doctor.
| Age | Possible signs to watch for |
|---|---|
| By 2 months | Does not smile back when you smile at them, does not look at your face |
| By 6 months | Few big, warm smiles, very limited eye contact |
| By 9 months | No back-and-forth sounds, smiles, or faces, does not look when you call their name |
| By 12 months | No gestures like waving or reaching to be picked up, no babbling, no response to name |
| Watch for | Stiffening of arms or legs, unusual body movements, rarely seeking your attention, delays in rolling, sitting, or crawling |
Can you tell if a baby has autism?
You cannot diagnose autism in a baby, but you can spot early signs. Researchers at places like the Kennedy Krieger Institute have identified infant signs such as limited eye contact, not smiling back, and not responding to their name. These are reasons to watch closely and talk to your doctor, not a diagnosis.
“Did your 'mom gut' just know before you were told by a doctor?”
Parents on r/Autism_Parenting answered with real infant signs: fleeting eye contact, not reaching up to be picked up, and not responding to their name. Many trusted that gut feeling long before a doctor confirmed it.
Parent in r/Autism_Parenting, “first signs in your baby” thread · read the thread →
Do autistic babies make eye contact and respond to their name?
Often less than other babies. By 2 months most babies look at faces, and by 9 months most look when you call their name. A baby who rarely does either, even when they can hear well, is showing a sign worth raising at the next checkup.
Are there physical signs of autism in babies?
Sometimes. Beyond social signs, some autistic babies show stiff arms or legs, unusual movements, or developmental delays in rolling, sitting, or crawling. They may rarely reach up to be picked up. These motor and social signs together are more telling than any single one.
Do autistic babies smile?
Many do. A smile does not rule out autism. What researchers watch for is fewer warm, shared smiles aimed back at you, especially the big social smiles most babies give by 6 months.
Should I wait and see, or act now?
Act now. Waiting is the most common regret parents share. If you have a real concern, you can start a free Early Intervention Colorado evaluation yourself, without a diagnosis and at no cost. Starting early keeps the most doors open.
What to do next in Colorado
Babies are exactly who Early Intervention Colorado is built for. It serves children from birth to age 3, free, and you can refer your own child.
| Your child's age | Where to start in Colorado (free) | What happens |
|---|---|---|
| Birth to age 3 | Early Intervention Colorado (call 1-888-777-4041, or refer yourself) | A free evaluation and services, with no cost and no diagnosis needed first. |
| Age 3 and older | Child Find through your local school district | A free evaluation, finished within 60 days of your written okay. |
| Any age | Your pediatrician | An autism screen (M-CHAT-R) at the 18- and 24-month visits, then a referral for a full evaluation. |
| After a diagnosis | In-home ABA with a Colorado BCBA | Budding Futures builds the plan, checks your Medicaid or insurance, and starts with no current waitlist. |
After an autism diagnosis, Budding Futures provides in-home ABA across Colorado, works with Health First Colorado (Medicaid) and major insurers, and starts families with no current waitlist. A Board Certified Behavior Analyst, Rachel Blackburn, reviews each plan.
Sources
Plain-language summaries of autism signs come from these authorities. We link the originals so you can read them yourself.
Kennedy Krieger Institute, Early Signs in 6-12 Month-Olds
Research-backed early signs in infants, including motor and social signs.
CDC, Signs and Symptoms of Autism Spectrum Disorder
The federal list of autism signs, tied to specific ages from 9 months on.
CDC, Screening and Diagnosis of ASD
Signs can show by 18 months, and a reliable diagnosis is possible by age 2.
Early Intervention Colorado
Free evaluation and services for Colorado children birth to age 3.
CDC, Learn the Signs. Act Early. (Milestones)
Free milestone checklists from birth to age 5, with a Milestone Tracker app.
Not sure what you are seeing? Talk to a Colorado BCBA
We can talk through the signs, point you to the right free evaluation, and if your child has a diagnosis, build an in-home plan and check your Medicaid or insurance.