Formerly located only in the northeast part of the state, the district now encompasses the western parts of the Denver metropolitan area, including Golden, Lakewood, Arvada and Broomfield, along with the central Colorado counties of El Paso County, Jefferson, Park, Teller, Lake, Chaffee, Fremont, and Custer.

The boundaries were drawn by a court after the state legislature failed to agree on a redistricting plan.

Since then, a growing Democratic trend in the Denver suburbs allowed Perlmutter to strengthen his hold on the seat.

Redistricting after the 2010 census shifted the district to the more populated portions of Jefferson County, making it slightly more Democratic.

The 2020 census has changed the district significantly, absorbing the rural areas in the central portion of the state.