M-CHAT-R Autism Screening for 21-Month-Olds
At 21 months, social communication is well-developed enough for the M-CHAT-R to give a clear and reliable picture. Whether you are completing this as a routine screen or following up on specific concerns, 21 months is a good time to capture your child's current behaviours.
- Questions
- 20
- Format
- Yes / No
- Time
- ~5 minutes
- Completed by
- Parent or caregiver
- Age range
- 16–30 months
About the M-CHAT-R
By 21 months, children typically use two-word phrases regularly, show clear social engagement — making eye contact, laughing with others, and initiating interaction — and are imitating household activities in play. Pointing to share interest should be consistent and spontaneous at this age.
The M-CHAT-R at 21 months is particularly useful for identifying children whose language development appears broadly on track but whose social communication quality — the back-and-forth, the shared interest, the responsiveness to others — may be different from expectations.
Source: Modified Checklist for Autism in Toddlers, Revised — Robins, Fein & Barton (2009)
Frequently asked questions
- My 21-month-old plays alone a lot. Is that typical?
- Parallel play — playing alongside but not directly with other children — is normal at this age. What the M-CHAT-R focuses on is social engagement with caregivers: eye contact, name response, and sharing attention on objects. Solitary play is not itself a red flag, but limited interest in social interaction with familiar adults is.
- My child passed the 18-month screen but I have new concerns. Should I screen again?
- Yes. The 18-month result is a snapshot, not a permanent clearance. Development changes quickly in the toddler years, and some autism presentations become clearer as social demands increase. If you have new concerns at 21 months, completing the M-CHAT-R again based on current behaviour is appropriate.
- What happens if my child screens at risk?
- A positive screen means enough reported behaviours are present to warrant further evaluation. The recommended next step is a referral to a developmental paediatrician, paediatric psychologist, or specialist autism diagnostic service. Early referral leads to earlier access to support.
- Does a positive screen mean my child has autism?
- No. A positive screen is not a diagnosis. Many children who screen positive do not receive an autism diagnosis after full evaluation. Only a qualified clinician carrying out a comprehensive assessment can diagnose autism spectrum disorder.
- How long does the screening take?
- Most parents complete the M-CHAT-R in 3 to 5 minutes. Results and guidance are available immediately after the last question.
Free · Private · Results in under 15 minutes