ZIP Codes of Johnson County, IA

Population & People
Population & People
Total Population
153,959
Household Income
Household Income
Median Income
$86,817
Housing
Housing
Total Housing Units
67,160
Business & Economy
Business & Economy
Total Businesses
3,428
Employment
Employment
Employment Rate
66.86%
Education
Education
Bachelor's Degree+
55.61%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 14 ZIPs in this county.
Data Last Updated: June 1, 2026
ZIP Codes:14 ZIP Codes (11 Standard, 2 PO Box, 1 Unique) [See All]
Area Code:319
Timezone:Central (GMT -06:00)
Local Time:2:11:53 PM
Population:153,959 [See All]
FIPS:19103
CBSA:Iowa City, IA
Land Area:515 sq mi
Water Area:10 sq mi
Coordinates:41.6766, -91.5693
Quick Link:
https://www.zip-codes.com/county/ia-johnson.asp
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Iowa's most-educated county
55.6% of adults 25+ have a bachelor's degree+.
Extreme geographic sprawl
The largest ZIP spans 205× the smallest by area — 141.5 sq mi down to 0.69.
Among Iowa's 5 most populous counties
#4 of 99 counties with 153,959 residents.
Among Iowa's 5 fastest-growing counties
#4 statewide, up 15.0% from 2014 to 2024.
Striking education divide
Bachelor's share spans 21.4% to 67.3% — a 46-point gap.
Among Iowa's 5 most renter-heavy counties
40.8% of homes rented — #2 statewide.

Standout ZIPs in this County


Most Populous
Iowa City · 35,074 people
22.8% of county total
Highest Income
Swisher · $119,605 median
1.4× county average
Largest Land Area
Iowa City · 141.5 sq mi
Spans the most ground
Fastest Growth
Tiffin · 212.2% (10-yr)
1,963 → 6,128 residents
Most Educated
Iowa City · 67.3% bachelor's+
8,768 of 13,035 adults 25+

Things worth knowing about Johnson County


153,959 residents live across 14 ZIPs covering 515 sq mi, served by 9 distinct USPS-recognized cities.

Population moved from 133,920 to 153,959 from 2014 to 2024 — a +15.0% change. 9 ZIPs gained residents, 3 lost.

The county's wealthiest ZIP 52338 (Swisher, $119,605 median) and poorest ZIP 52240 (Iowa City, $52,960) are 18.1 miles apart — a 2.3× income gap across local geography.

Median home values vary 1.6× across this county — from $240,200 in 52235 (Hills) to $392,700 in 52338 (Swisher).

Density varies 270× across the county — from 25 people/sq mi in 52322 (Oxford) to 6,782 in 52242 (Iowa City).

Educational attainment ranges from 21.4% bachelor's+ in 52755 (Lone Tree) to 67.3% in 52246 (Iowa City) — the breadth of educational profiles across the area.

Within Iowa, this is the #4 most populous of 99 counties and ranks #11 for median household income with the #4 fastest decade growth .

Hosts 1 single-entity Unique ZIP: 52243American College Testing .

Weighted by population, the typical household earns about $76,764 across the county — reflecting what a typical resident sees, not a simple ZIP average.

55.6% of adults age 25+ hold a bachelor's degree or higher (51,263 of 92,178 reporting). The most-educated ZIPs cluster around Iowa City.

11 Standard delivery, 2 PO Box only, 1 single-entity Unique ZIPs serve this county.

Stories about Johnson County


Higher-education hub

3 ZIPs in this county where more than 60% of adults 25+ hold a bachelor's degree — typically college campuses, research enclaves, or tech corridors.

Iowa City
67.3%
22,308 residents
Iowa City
67.2%
22,853 residents
Tiffin
60.7%
6,128 residents

All ZIP Codes in Johnson County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
52240Iowa CityStandard35,074$52,960141.55.4%
52241CoralvilleStandard23,250$69,24313.818.0%
52317North LibertyStandard23,097$105,31838.142.5%
52245Iowa CityStandard22,853$78,0209.0-2.3%
52246Iowa CityStandard22,308$62,52116.5-0.7%
52333SolonStandard7,295$118,72194.07.9%
52340TiffinStandard6,128$98,39318.1212.2%
52242Iowa CityStandard4,6880.7180.7%
52338SwisherStandard3,934$119,60530.418.4%
52322OxfordStandard2,266$64,44490.3-3.9%
52755Lone TreeStandard2,092$102,43460.95.2%
52235HillsPO Box974$83,3331.721.6%
52244Iowa CityPO Box0.0
52243Iowa CityUnique0.0

Adjacent & Nearby Counties