Inclusion Criteria:

• age between 16-48 months,
• parental consent
• being on a waitlist to receive a formal diagnostic evaluation at the time of parent consent due to autism concerns
• parents speak English
• an initial score of 8 or greater or Follow-Up score of 2 or greater on the Modified Checklist for Autism in Toddlers, Revised, with Follow-Up (M-CHAT-R/F; Robins et al., 2014) as an indication of autism likelihood.

Exclusion Criteria:

• having already received a formal diagnosis of autism
• enrollment in early intervention programs delivering more than 5 h per week of evidence-based autism-specific interventions at the time of consent
• child has a gestational age less than 36 weeks associated with a birth weight less than 2500 g
• the child is not yet walking, or has severe hearing and/or vision impairment that is uncorrected with aids, or known neurological disorder or genetic syndrome (e.g., Down syndrome).