East and Southern Africa is home to 6.2% of the world's population but includes 54% of all people living with HIV (PLWH). In this region, three out of five PLWH are women, and there is a particularly high burden of HIV amongst adolescent girls and young women (AGYW). Over half of African women use family planning (FP) services. Integration of HIV prevention and treatment with FP services holds promise for supporting progress toward the UNAIDS 95-95-95 targets for testing, treatment, and prevention. Nonetheless, integration of even basic HIV prevention and treatment services into FP clinics remains low and how best to integrate these services is still unknown. In a previous trial, the Systems Analysis and Improvement Approach (SAIA), was an effective implementation strategy for improving HIV counseling and testing in a small selection of FP clinics in Mombasa County, Kenya when delivered by research staff. SAIA incorporates a cascade analysis tool, sequential process flow mapping, and cycles of micro-intervention development, implementation, and assessment to improve a care cascade. More data is needed to understand if SAIA is effective for also improving linkage to HIV care and screening and linkage to pre-exposure prophylaxis (PrEP) in FP clinics when SAIA is delivered at scale by Kenyan public health workforce. The first objective of this study is to conduct a cluster-randomized trial evaluating the effectiveness of SAIA versus control (usual procedures with no specific intervention) for increasing HIV counseling, testing, linkage to HIV care, and screening and linkage to PrEP in new FP clients and new and returning AGYW clients. There will be a particular focus on the HIV prevention and treatment of AGYW in this study and any AGYW presenting for FP care will be prioritized. Quantitative and qualitative data will be analyzed using the RE-AIM framework to evaluate the program's Reach, Effectiveness, Adoption, Implementation, and Maintenance. To understand how SAIA could be integrated into national Ministry of Health policies and programs, activity-based costing will be conducted to estimate the budget and program impacts of SAIA, scaled to a County level, from a Ministry of Health perspective. It is hypothesized that compared to control, SAIA will be effective at increasing HIV counseling, HIV testing, linkage to HIV care, and screening and linkage to PrEP for new FP clients and all new and returning AGYW FP clients when delivered at scale by Kenyan public health staff. The implementation evaluation, costing, and budget impact analysis will establish a road map for national-level implementation, positioning Kenya as a global leader in integrating FP/HIV services.