At 20 months old, it’s too early to know for certain whether your child is autistic from observation alone, but it’s exactly the right time to pay attention. Many of the earliest signs of autism become visible between 18 and 24 months, and the average age of skill regression in children later diagnosed with autism is right around 20 months. The fact that you’re watching closely puts you in the best possible position to act early if needed.
Here’s what to look for, what’s typical at this age, and what steps to take if something feels off.
What a 20-Month-Old Typically Does
By this age, most children are building a toolkit of social and communication skills that go well beyond first words. Your child should be using gestures beyond waving and pointing, things like blowing a kiss, nodding yes, or shaking their head no. They should be able to point to things in a book when you ask (“Where’s the dog?”) and identify at least two body parts when prompted.
Most children this age are also starting to string two words together: “more milk,” “daddy go,” “big truck.” They notice when someone else is upset, pausing or looking sad when another child cries. They look at your face in unfamiliar situations to figure out how they should react. These social-emotional responses are just as important as language milestones, and sometimes more telling.
Early Signs That May Point to Autism
No single behavior means your child is autistic. What matters is the overall pattern, especially when several of these signs appear together:
- Not responding to their name. If you say your child’s name and they consistently don’t look up or turn toward you, even when there’s no competing distraction, that’s worth noting.
- Limited eye contact. All toddlers look away sometimes, but a child who rarely makes eye contact during play, feeding, or conversation is showing a potential red flag.
- Not smiling back. When you smile at your child, they should smile in return. A child who doesn’t mirror your facial expressions may have difficulty with social reciprocity.
- Few or no gestures. By 20 months, your child should point at things to show you, not just to ask for them. Holding up a toy to share it with you, waving, nodding: these are all forms of nonverbal communication that typically develop well before this age.
- Repetitive movements. Hand flapping, finger flicking, rocking, or spinning objects repeatedly can be a sign, particularly when they happen frequently or seem to replace other types of play.
- Little or no pretend play. By this age, most children are beginning to pretend: feeding a stuffed animal, talking into a toy phone. A child who lines up toys instead of playing with them imaginatively may be showing a restricted play pattern.
- Extreme reactions to sensory input. Getting very distressed by certain sounds, textures, lights, or food textures can signal sensory processing differences common in autism. Some children are the opposite, seeming unusually unresponsive to pain or temperature.
- Limited speech. While some children are simply late talkers, a 20-month-old who uses very few words, repeats the same phrases without clear meaning, or has stopped using words they once had is showing a pattern worth investigating.
Joint Attention: The Sign Parents Often Miss
One of the most important early indicators is something called joint attention, and it’s easy to overlook because it doesn’t involve words. Joint attention is the back-and-forth of sharing interest in something. Your child sees a dog outside, points at it, then looks back at you to make sure you see it too. Or you point at an airplane and your child follows your gaze to find it.
This might seem small, but it’s actually a foundational social skill. It shows your child understands that other people have their own perspective and that experiences can be shared. Children who later receive an autism diagnosis often show reduced joint attention early on. They may point to request things they want but rarely point just to share something interesting. They may not follow your gaze or look where you’re pointing.
Speech Delay vs. Autism
Many parents searching for autism signs are really noticing that their child isn’t talking as much as other kids. A speech delay alone doesn’t mean your child is autistic. Some children are simply late talkers who catch up on their own or with a bit of speech therapy.
The difference lies in everything surrounding the speech. A child with an isolated speech delay typically still makes eye contact, uses gestures to communicate, responds to their name, engages in pretend play, and shows interest in other children. A child whose speech delay comes alongside reduced eye contact, limited gestures, repetitive behaviors, and difficulty with social back-and-forth is showing a broader pattern that’s more consistent with autism. The social and behavioral signs are what distinguish the two.
Skill Loss Around This Age
About one-third of children who are eventually diagnosed with autism experience a regression, losing skills they previously had. This typically happens during the second or third year of life, with the average age of regression falling right around 20 months. The most common loss is speech: a child who was saying 10 or 15 words gradually stops using them. But regression can also involve social skills (a child who used to wave stops doing so) or play skills.
If your child has lost words or social behaviors they clearly had before, that’s one of the more urgent reasons to seek an evaluation. Regression doesn’t always mean autism, but it should always be assessed.
How Screening Works
The standard screening tool for autism in toddlers is a questionnaire called the M-CHAT-R. Your pediatrician may have already given it to you at the 18-month well-child visit. It’s a 20-question yes-or-no checklist that you fill out based on your child’s behavior. The questions cover things like whether your child points, follows your gaze, responds to their name, and shows interest in other children.
A score of 0 to 2 is considered low risk. A score of 3 to 7 puts your child in a medium-risk range, and the pediatrician will typically ask follow-up questions to clarify. A score of 8 or higher is high risk, and a referral for a full evaluation is recommended right away. It’s important to know that this screening tool is designed to cast a wide net. It catches many children who turn out not to have autism. A positive screen is not a diagnosis; it’s a reason to look more closely.
If your child hasn’t been screened yet, you can ask your pediatrician to administer it, or you can find the questionnaire through your pediatrician’s office.
What a Full Evaluation Looks Like
If screening suggests a concern, the next step is a formal developmental evaluation. This is done by specialists such as a developmental pediatrician, child psychologist, speech-language pathologist, or occupational therapist, sometimes working as a team. The evaluation involves observing your child directly, giving them structured activities to see how they respond, and asking you detailed questions about their behavior at home. Some evaluators will also ask you to fill out additional questionnaires.
A formal diagnosis of autism requires persistent differences in two broad areas: social communication (how your child interacts, uses gestures, makes eye contact, and relates to others) and restricted or repetitive behaviors (repetitive movements, rigid routines, intense fixations, or unusual sensory responses). A child needs to show difficulties across all three aspects of social communication plus at least two types of repetitive behavior to meet the diagnostic criteria. In some cases, the specialist may also recommend genetic testing.
Wait times for evaluations can be long, sometimes several months. If you’re concerned, request the referral now rather than waiting.
You Don’t Need a Diagnosis to Get Help
One of the most important things to know is that your child can receive early intervention services before a formal autism diagnosis. Under federal law, children under age 3 who have a developmental delay in communication, social-emotional skills, or other areas are eligible for early intervention through their state’s Part C program. You don’t need a doctor’s referral in most states; you can contact your state’s early intervention program directly and request an evaluation.
This matters because the months between noticing a concern and receiving a diagnosis can stretch on, and early intervention during that window can make a real difference. Services might include speech therapy, occupational therapy, or developmental support tailored to your child’s specific needs. About 1 in 31 children in the U.S. is eventually identified with autism, and outcomes are consistently better when support starts early. If your gut is telling you something is different about your child’s development, acting on that instinct now is the single most useful thing you can do.