Objectives: The aim of this study was to assess HIV modes of exposure in Morocco at the national level and also for Souss-Massa-Drâa, the region most affected by HIV. Another aim was to assess the impact of different scenarios of select intervention packages. Methods: The Modes of Transmission Model was adapted and used, and was parameterized using quality bio-behavioral surveillance data among key populations, routine data sources, and literature reviews. Results: Nationally in 2013, the largest number of new infections occurred among clients of female sex workers (FSWs) (25%; 95% confidence interval (CI) 14–37%), followed by men who have sex with men (MSM) (22%; 95% CI 12–35%), HIV serodiscordant couples (22%; 95% CI 12–34%), FSWs (11%; 95% CI 6–18%), and people who inject drugs (5%; 95% CI 2–9%). A similar pattern of results was observed in Souss-Massa-Drâa, but the HIV incidence rate was four-fold that at the national level. Different scenarios of feasible intervention packages reduced HIV incidence by 8–44%. Conclusions: Commercial heterosexual sex networks continue as the leading driver of the epidemic, with half of HIV incidence. A quarter of new infections occurred among MSM, a third of which in Souss-Massa-Drâa. Feasible expanded coverage of interventions could lead to large reductions in incidence. Keywords: Mathematical model, Modes of transmission, Interventions, Morocco, Middle East and North Afric
