The Foundations for Digital Twins as Catalyzers of Biomedical Technological Innovation (FDT-BioTech) program supports inherently interdisciplinary research projects that underpin the mathematical and engineering foundations behind the development and use of digital twins and synthetic data in biomedical and healthcare applications, with a particular focus on digital, in silico models used in the evaluation of medical devices and the relevance of the developed models in addressing current and emerging challenges affecting the development and assessment of biomedical technologies. The goal of the FDT-BioTech initiative is to catalyze biomedical technological innovation through new foundational development of methods and algorithms relevant to digital twins and synthetic humans.