The USTUR’s 2023 Annual Report has been completed and is available for download. The document summarizes organization, activities, and scientific accomplishments at the USTUR from April 1, 2022 to March 31, 2023 (fiscal year 2023). Research summaries include: bias in plutonium systemic and lung activity predictions, use of USTUR data to develop site-specific biokinetic models for dose reconstruction at the Rocky Flats Plant, modeling chelation for a female nuclear worker, and misclassification of underlying causes of death.