Abstract Young children with disabilities are less likely to display age-appropriate social behaviors than same-age peers with typical social development, especially children who display social-communication delays. In this study, two concurrently operating single case designs were used to evaluate the use of progressive time delay (PTD) to teach children with disabilities to share and to name peer preferences during dyadic instruction. PTD was effective for teaching children to share and to identify peer preferences. All participants generalized 50 to 100% of peer preference targets to typical classroom activities (e.g., selecting their peer's preferred snack before mealtime), with mixed results regarding sharing during an art activity. Keywords: systematic instruction, sharing, peer preferences, preschool, young children ********** Pro-social behaviors influence the development of friendships beginning in early childhood (Odom, Schertz, Munson, & Brown, 2004), potentially impacting long-term success in academic and social settings (Lane, Stanton-Chapman, Jamison, & Phillips, 2007). High-quality preschool programs focus on increasing pro-social behaviors in young children with and without disabilities (Division for Early Childhood [DEC] and National Association for the Education of Young Children [NAEYC], 2009; Wolery, 2005), providing numerous opportunities for interactions (Grisham-Brown, Hem meter, & Pretti-Frontczak, 2005). However, young children with disabilities are more likely to display social delays that impede appropriate peer interactions, potentially leading to rejection from peer groups (Guralnick, 1999). Young children with disabilities may require structured opportunities for peer-to-peer interactions to recognize the potentially "complex discriminative stimuli" that set the occasion for age-appropriate social behaviors (Ledford & Wolery, 2013, p. 440). Increasing age-appropriate pro-social behaviors in young children with disabilities requires practitioners to select target behaviors common in peer-to-peer interactions. Pro-social behaviors, such as initiating conversations (e.g., commenting on a peer's preferred interest), helping behaviors (providing assistance or aid), and sharing items with peers (giving an item so a peer can engage in or have the same or similar materials during an activity), are behaviors young children with typical social development commonly demonstrate in preschool classrooms (e.g., Babcock, Hartle, & Lamme, 1995). In addition, young children are more likely to identify peers who help and share items as "nice" and as "friends" (Tisak, Holub, & Tisak, 2007), potentially leading to increases in meaningful peer-to-peer interactions. Young children with social-communication delays (SCD), such as autism spectrum disorder (ASD), are less likely to initiate and attend to peers' social initiations than children with intellectual disability or typical development (Bregman & Higdon, 2012) and may display difficulties taking the perspective of others (known as Theory of Mind Impairments [ToM]; Millward, Powell, Messer, & Jordan, 2000; Mundy & Thorp, 2006; Zager, Wehmeyer, & Simpson, 2012), indicating a need for evidence-based interventions that directly teach pro-social behaviors with peers (Reichow & Volkmar, 2010; White, Keonig, & Scahill, 2007; Wolery & Hemmeter, 2011). Direct instruction regarding peer preferences may increase pro-social behaviors by providing contextual support when teaching helping and related behaviors (e.g., conversation skills). One study assessed learning a peer's preferences by presenting this information as instructive feedback during small group academic instruction; all participants learned some of the information without direct instruction, but generalization was not assessed (Lane, Gast, Shepley, & Ledford, 2015). Although knowing a peer's preferences may set the occasion for pro-social behaviors (e. …