The ethnic composition of US scientists and engineers is undergoing a significant transformation. This study applies an ethnic-name database to individual patent records granted by the United States Patent and Trademark Office to document these trends with greater detail than previously available. Most notably, the contributions of Chinese and Indian scientists to US technology formation increase dramatically in the 1990s, before noticeably leveling off after 2000 and declining in the case of India. Growth in ethnic innovation is concentrated in high-tech sectors; the institutional and geographic dimensions are further characterized.