The NSF Division of Astronomical Sciences (NSF-AST) supports versatile facility suites in gamma-ray astronomy, optical and infrared astronomy, millimeter and submillimeter astronomy, radio astronomy, and solar astronomy (Box 6.2). The ground-based optical and infrared (OIR) telescopes operate from 0.3 to 20 micrometers and include facilities for both night-time astronomy and for day-time solar studies. The ground-based radio telescopes operate at submillimeter to centimeter wavelengths. For all of these facilities the observing time is competed, typically through bi-annual or tri-annual proposal processes. About $250 million of the roughly $300 million total astronomy and astrophysics expenditures flows through NSF-AST. The remainder is associated with NSF’s Division of Physics (NSF-PHY; including particle and nuclear astrophysics), Division of Atmospheric and Geospace Sciences (NSF-AGS), and Office of Polar Programs (NSF-OPP).