Abstract. The UN 2030 Agenda and Sustainable Development Goals (SDGs) call for disaggregating results of program effectiveness within subgroups. Using the Bornstein (2017) specificity principle, involving within-group assessments regarding what specific youth prosper in what specific ways in what specific programs, we analyzed data from 888 Salvadoran youth (50% female), aged 9–15 years ( M = 11.60 years, SD = 1.7), participating in the Compassion International (CI) Study of Positive Youth Development (PYD). We compared CI-supported youth with non-CI-supported youth on nine variables related to PYD, intentional self-regulation, hopeful future expectations, and spirituality. Whereas tests of group averages indicated no meaningful differences, disaggregated results across 20 program sites indicated that 2 sites showed no group differences, 7 sites showed better CI-supported youth performance, 3 sites showed better non-CI-supported youth performance, and 8 sites showed a mixed pattern. We discuss the use of the specificity principle in future assessments of SDG indicators.