Boundary Atlas

Connecticut: cities, counties, ZIP codes and districts

Connecticut has 5 congressional districts, 36 state senate districts and 151 state house districts under the maps in force for November 3, 2026, plus 730 voting precincts, 9 counties, 215 cities, towns and Census-designated places, and 288 ZIP codes.

Cities and towns

Largest first. Each page lists the city's county, districts and ZIP codes.

Congressional districts (2026)

DistrictShort2020 population
Connecticut's 1st congressional districtCT-01721,189
Connecticut's 2nd congressional districtCT-02721,188
Connecticut's 3rd congressional districtCT-03721,189
Connecticut's 4th congressional districtCT-04721,189
Connecticut's 5th congressional districtCT-05721,189

ZIP codes in Connecticut

Each page lists the ZIP's congressional and legislative districts, with population shares where it's split.

Get this in your AI agent

Your agent can list, look up and map every district and precinct in Connecticut. Add https://atlas-production-d344.up.railway.app/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:

list_geographies(country="US", level="congressional_district", region="CT")