Geographic Regions and Area Codes

Area Code 983 covers a significant portion of central Colorado, including major cities such as Denver, Boulder, and Aurora. It also encompasses surrounding suburbs like Lakewood, Littleton, Longmont, Broomfield, and Castle Rock. The region is divided into several counties, including Adams, Arapahoe, Boulder, Broomfield, Clear Creek, Denver, Douglas, Gilpin, Jefferson, and Weld. This area code is an overlay of the original Area Code 303 and the subsequent Area Code 720. This means that the same geographic region is served by all three area codes: 303, 720, and 983.

Key regions and their area codes:

  • Denver: 303, 720, 983
  • Boulder: 303, 720, 983
  • Aurora: 303, 720, 983
  • Lakewood: 303, 720, 983
  • Littleton: 303, 720, 983
  • Longmont: 303, 720, 983
  • Broomfield: 303, 720, 983
  • Castle Rock: 303, 720, 983