CDC’s Division of STD Prevention has two existing cost modeling tools that state and local STI programs can use for planning, resource allocation decisions, and advocacy for additional state resources. This project aims to update and enhance these tools to incorporate the most recent scientific information and meet the usability requirements and information needs of end-users. Activities include collecting updated model estimates, soliciting end users’ input on model enhancements, creating enhanced models that incorporate updated scientific research and end users’ feedback into the interface, and testing model prototypes to ensure they meet design requirements.