Boundary Atlas

ZIP code 52228: Fairfax, IA

ZIP code 52228 is in Fairfax (83% of residents), in Linn County (96%), Benton County (2.3%) and Johnson County (1.7%), Iowa. 17% of its residents live outside city limits. It is in Iowa's 2nd congressional district (98%) and Iowa's 1st congressional district (1.7%). Its state senate districts are State Senate District 42 (98%) and State Senate District 46 (1.7%); its state house districts are State House District 84 (98%) and State House District 91 (1.7%).

3,402residents (2020 Census)
37.2 sq miland area
2cities and towns
2congressional districts
6voting precincts

See it on the mapAll of Iowa

City and county

City or townShare of ZIP residents
Fairfax83%
Cedar Rapids0.3%

CountyShare of ZIP residents
Linn County96%
Benton County2.3%
Johnson County1.7%

Town or county subdivisionShare of ZIP residents
Fairfax township96%
Monroe township1.7%
Florence township1.5%
Fremont township0.8%
Cedar Rapids city0.3%

Congressional districts

Congressional districtShare of ZIP residents
Iowa's 2nd congressional district (IA-02)98%
Iowa's 1st congressional district (IA-01)1.7%

This ZIP is split between districts. A mailing address in it could be in either; the map or locate_point gives the district for an exact address.

State legislative districts

State senate districtShare of ZIP residents
State Senate District 4298%
State Senate District 461.7%
State Senate District 39land only

State house districtShare of ZIP residents
State House District 8498%
State House District 911.7%
State House District 77land only

Voting precincts

6 voting precincts overlap ZIP 52228. 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:52228")

ZIP 52228 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.