Boundary Atlas

ZIP code 46403: Gary, IN

ZIP code 46403 is in Gary, in Lake County (100%) and Porter County (<0.1%), Indiana. It is in Indiana's 1st congressional district. Its state senate district is State Senate District 3; its state house district is State House District 3.

11,649residents (2020 Census)
9.1 sq miland area
1cities and towns
1congressional district
10voting precincts

See it on the mapAll of Indiana

City and county

City or townShare of ZIP residents
Gary100%

CountyShare of ZIP residents
Lake County100%
Porter Countyland only

Town or county subdivisionShare of ZIP residents
Calumet township100%
Portage townshipland only

Congressional district

Congressional districtShare of ZIP residents
Indiana's 1st congressional district (IN-01)100%

State legislative districts

State senate districtShare of ZIP residents
State Senate District 3100%
State Senate District 4land only

State house districtShare of ZIP residents
State House District 3100%
State House District 10land only

Voting precincts

10 voting precincts overlap ZIP 46403. Map them, with each precinct's share of the ZIP's residents.

Get this in your AI agent

Your agent can get these cities, counties, districts and precincts with their shares, and their GeoJSON boundaries, from Boundary Atlas. Add https://atlas-production-d344.up.railway.app/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:

related_geographies(id="us:zcta:46403")

ZIP 46403 here is the Census Bureau's ZIP Code Tabulation Area, which approximates the USPS ZIP Code; PO-box-only ZIPs have none. Districts are the maps in force for the November 3, 2026 election.