OBJECTIVES/GOALS: The objective of this study is to examine the independent and combined effectiveness of a multiple micronutrient supplementation and responsive caregiving intervention on early child development in southwestern Guatemala. METHODS/STUDY POPULATION: We conducted a double blind, 2 x 2, cluster randomized controlled trial combining micronutrient supplementation and responsive caregiving treatments. We enrolled 309 infants (6-18 months) and 387 preschoolers (36-52 months) at nutritional risk (height-for-age z-score < -1) (51% male; 17% indigenous ethnicity; 76% of caregivers completed ≤ primary school). The supplementation arm received a maize-soy product fortified with 21 micronutrients for 6 months; the control was fortified with B2. The responsive caregiving intervention was adapted from the UNICEF Care for Child Development program and delivered over 6 home visits. We examined changes in early child development from baseline (2015) to endline (2017) using the Bayley Scales of Infant and Toddler Development III and Bracken Scales of School Readiness. RESULTS/ANTICIPATED RESULTS: Among infants, age standardized Bayley cognitive development scores declined over time in each treatment arm. Infant Bayley motor development scores significantly increased in the combined multiple micronutrient supplementation + responsive caregiving arm (â^† = 3.67 [95% CI: 0.17, 7.17], p = 0.04). Among preschoolers, school readiness decreased over time in each treatment arm. The rates of change in infant development and preschooler school readiness did not differ between treatment arms. Further analysis will explore effect modification of the intervention by pre-specified child and household factors. DISCUSSION/SIGNIFICANCE: Combined multiple micronutrient supplementation and responsive caregiving supported motor development while cognitive and school readiness were not impacted by the intervention. These findings will inform the effectiveness and beneficiaries of multisectoral interventions to promote early child development in adverse environments.