This study examines the role played by access to caring and engaging adults, career search self-efficacy (CSSE), and goal capacity in the development of youth vocational identity. The study used a bootstrapping approach to analyze data, collected from a survey of 1,579 youths enrolled in 14 U.S. high schools, to test a hypothesized serial multiple mediation model. Results indicate both direct and multiple indirect pathways from adults influences to the youth vocational identity. Two specific pathways of influence were found through CSSE and goal capacity respectively. Additionally, a serial multiple mediation effect was found whereby CSSE and goal capacity collectively mediated the relationship. This indicates that greater access to caring and engaging adults contributes to higher CSSE, which accounts for a higher level of goal capacity, and eventually leads to the better vocational identity in youth. These findings establish notable implications for practices that are discussed in closing.