This project is an extension of analyses RTI International has been conducting for the Centers for Disease Control and Prevention (CDC) since 2012. RTI has programmed a national compartmental model for HIV/AIDS, so the purpose of this project is to broaden the scope of the modeling effort by (1) incorporating uncertainty analyses, (2) investigating how new cases of HIV are generated based on calibration of the model’s mixing matrix, (3) calculating cost-effectiveness of pre-exposure prophylaxis for men who have sex with men compared with improvements to the test and treat continuum, and (4) allocating optimal, national HIV prevention resources from a societal perspective and consideration of the role of public health.