While the term “transactional sex” has garnered increased attention, little is known about what it truly encompasses, or how it leads to HIV risk within the specific developmental period of adolescence. We therefore introduce a model to characterize why girls in in sub-Saharan Africa engage in transactional sex, and how this may contribute to their decisions around how, whether, and when to implement HIV/sexually transmitted infection (STI) prevention efforts. This model forms the foundation for our adolescent-specific HIV prevention efforts for young girls in sub-Saharan Africa. Within this topical review, we detail how this intervention has been adapted for cross-cultural fit and congruence, as well as for developmental factors in transactional sex decision-making, including practical avenues to navigate peer and partner risk. Together, this model and related HIV prevention program focus on empowering young girls in sub-Saharan Africa as they begin to make decisions about whether and when to engage in transactional sex, by providing girls with critical HIV risk reduction skills during this time of rapid transition into HIV/STI risk behavior. (PsycINFO Database Record (c) 2018 APA, all rights reserved)