The National Nanotechnology Initiative (NNI) is a crosscutting national vision for nanotechnology development in the United States. The Federal effort in nanotechnology coordinates U.S. investment in research and development (R&D) in nanoscale science, engineering, technology, and related activities across the U.S. Government. In FY2014, even though five agencies garnered 93 percent of the Federal spending in nanotechnology R&D, 27 agency units from 20 top‐level Federal entities participated in nanotechnology activities. The 21st Century Nanotechnology Research and Development Act of 2003 calls for a National Nanotechnology Advisory Panel to review the NNI periodically. Designated in 2004 to be that panel, the President’s Council of Advisors on Science and Technology (PCAST) has reviewed the NNI five times, and this report is the third of this Administration’s PCAST.