In May 2019, the SI will be redefined with units based on fundamental constants of nature. NIST’s role in this transition from a classical to a quantum definition will be one of leadership. NIST will explore the foundational limits of the Quantum SI by integrating efforts in fundamental research, applied research and dissemination of the SI units. NIST’s goal is to develop Quantum SI standards and sensors for mainstream US industry, and disruptively change the classical dissemination modality.