CO-4 · Colorado

Congressional District CO-4 includes 121 indexable ZIP codes in Colorado on US5, with a combined ZIP-area population of about 608,181.

Larger population clusters inside this district include Parker, CO, Highlands Ranch, CO, Castle Rock, CO, Windsor, CO, and Castle Pines, CO. Open any ZIP below for full demographics, housing, schools, and nearby services.

The most populous ZIP currently listed for CO-4 is 80134 (about 77,814 residents).

Across ZIPs with income data in CO-4, the average median household income is about $79,330 — about 6% above the U.S. median ($75,149).

Average median home value across those ZIPs is about $324,164.

On this page’s income ranking, ZIP 80108 is near the top at about $178,670.

Congressional districts are the geographic units that elect members of the U.S. House of Representatives. District CO-4 is one of Colorado's seats in the House; boundaries are redrawn after each decennial Census.

District lines are not the same as ZIP codes, cities, counties, area codes, or TV markets. A single ZIP can touch more than one district at the edges, and US5 maps each published ZIP to a primary district code for browseability.

US5 joins published ZIP profiles to congressional district codes so you can scan the district as a list of postal codes with population, income, and housing — then open any ZIP for maps, schools, commute, and climate context.

This is a place-based research view, not a voter roll, campaign tool, or live election results feed. Counts can change when geography publishes update.