RAPID is an ARPA-H program focused on improving diagnosis of rare and ultra-rare diseases. It aims to develop AI-based detection models and provider-facing tools that can fit into existing clinical workflows, as well as remotely deployable systems to help patients and families identify possible conditions and reach appropriate medical support. The program also seeks to bring fragmented patient data together into a curated longitudinal dataset for training and benchmarking diagnostic algorithms. Its announced work includes data infrastructure, diagnostic tools, and efforts to support research and treatment development.