Boundary Atlas

ZIP code 50229: Jefferson, IA

ZIP code 50229 is in Warren County (72%) and Madison County (28%), Iowa, outside any city or Census-designated place. It is in Iowa's 1st congressional district (72%) and Iowa's 3rd congressional district (28%). Its state senate districts are State Senate District 11 (72%) and State Senate District 12 (28%); its state house districts are State House District 22 (72%) and State House District 23 (28%).

1,029residents (2020 Census)
42.0 sq miland area
1cities and towns
2congressional districts
3voting precincts

See it on the mapAll of Iowa

City and county

City or townShare of ZIP residents
Bevington0.5%

CountyShare of ZIP residents
Warren County72%
Madison County28%

Town or county subdivisionShare of ZIP residents
Jefferson township64%
Crawford township28%
Jackson township8.0%

Congressional districts

Congressional districtShare of ZIP residents
Iowa's 1st congressional district (IA-01)72%
Iowa's 3rd congressional district (IA-03)28%

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.

Elected officials

OfficeMemberContactShare of residents
U.S. Representative (IA-01)Mariannette Miller-Meeks (R)202-225-657672%
U.S. Representative (IA-03)Zachary Nunn (R)202-225-547628%
U.S. SenatorChuck Grassley (R)202-224-3744 · contact formstatewide
U.S. SenatorJoni Ernst (R)202-224-3254 · contact formstatewide
State Senator (State Senate District 12)Amy Sinclair (R)28%
State Representative (State House District 22)Samantha Fett (R)72%
State Representative (State House District 23)Bubba Sorensen (R)28%

Officials serving now (members of Congress until January 3, 2027). Sources: State legislators: Open States (public domain); Members of Congress: the @unitedstates project, congress-legislators (CC0).

Local government

State legislative districts

State senate districtShare of ZIP residents
State Senate District 1172%
State Senate District 1228%

State house districtShare of ZIP residents
State House District 2272%
State House District 2328%

Voting precincts

3 voting precincts overlap ZIP 50229. 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:50229")

ZIP 50229 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.