The Determined, Resilient, Empowered, AIDS-free, Mentored, and Safe (DREAMS) program delivers community- and clinic-based interventions to reduce HIV vulnerability among adolescent girls and young women (AGYW) aged 15–24 years. We conducted a retrospective programmatic financial cost analysis from the implementing partner perspective using financial and programmatic records from October 2022 to June 2023. We estimated the total costs and cost per AGYW enrolled (cost/AGYW) of DREAMS components in Gaza and Inhambane, Mozambique. A total of 19,477 AGYW were enrolled in Gaza and 3320 in Inhambane from October 2022 to June 2023. Clinic-based components cost US$189,047 in Gaza and US$67,826 in Inhambane, which amount to US$10 and US$20 per AGYW enrolled, respectively. Inhambane’s community component cost US$128,344, and US$39 per AGYW enrolled without Siyakha (an economic package that prepares AGYW to enter the job market). Among Siyakha recipients, the combined community and Siyakha cost was US$466 for 59 AGYW receiving the light package without internship and US$551 for 54 AGYW receiving the full package with internship. Human resources were the largest cost category across components, indicating that staffing requirements are a major determinant of DREAMS implementation costs. Human resources were the main cost driver in both components, highlighting the need to optimize staffing models.