ZIP code 50138: Knoxville, IA

ZIP code 50138 is in Knoxville (65% of residents), in Marion County, Iowa. 35% of its residents live outside city limits. It is in Iowa's 1st congressional district. Its state senate districts are State Senate District 11 (92%) and State Senate District 19 (7.6%); its state house districts are State House District 21 (92%) and State House District 37 (7.6%).

11,631residents (2020 Census)

168.2 sq miland area

1cities and towns

1congressional district

11voting precincts

See it on the map All of Iowa

City and county

City or town	Share of ZIP residents
Knoxville	65%

County	Share of ZIP residents
Marion County	100%

Town or county subdivision	Share of ZIP residents
Knoxville township	90%
Indiana township	4.4%
Washington township	2.4%
Union township	2.1%
Clay township	0.7%
Franklin township	0.5%
Pleasant Grove township	0.1%

Congressional district

Congressional district	Share of ZIP residents
Iowa's 1st congressional district (IA-01)	100%

Elected officials

Office	Member	Contact	Share of residents
U.S. Representative (IA-01)	Mariannette Miller-Meeks (R)	202-225-6576	100%
U.S. Senator	Chuck Grassley (R)	202-224-3744 · contact form	statewide
U.S. Senator	Joni Ernst (R)	202-224-3254 · contact form	statewide
State Senator (State Senate District 19)	Ken Rozenboom (R)		7.6%
State Representative (State House District 21)	Brooke Boden (R)		92%
State Representative (State House District 37)	Barb Kniff McCulla (R)		7.6%

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

Knoxville website: https://www.knoxvilleia.gov/
Knoxville laws: search for the Knoxville, Iowa code of ordinances
Marion County website: https://www.marioncountyiowa.gov/
Marion County laws: search for the Marion County, Iowa code of ordinances

State legislative districts

State senate district	Share of ZIP residents
State Senate District 11	92%
State Senate District 19	7.6%

State house district	Share of ZIP residents
State House District 21	92%
State House District 37	7.6%

Voting precincts

11 voting precincts overlap ZIP 50138. 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:50138")

ZIP 50138 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.