Jefferson County, Iowa Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 48th-largest in Iowa
The population of Jefferson County, Iowa is 15,676 as of the 2023 American Community Survey, making it the 48th-largest county in Iowa. The median household income is $56,824, the median home value is $161,200, and the median age is 43.5.
The population of Jefferson County has declined 6.3% since 2010 (16,835 → 15,781), a -0.46% annualized rate.
15,676
Population
-0.46%
Annual growth
36
People / sq mi
$56,824
Median Income
$161,200
Median Home Value
Jefferson County covers 436 sq mi of land at 36.0 people per square mile.
About Jefferson County, IA
Jefferson County is a county in Iowa with a population of 15,676. It ranks #48 among counties in Iowa by population. The median age is 43.5, older than the national median. The population is 51.5% male and 48.5% female.
The median household income in Jefferson County is $56,824, below the US median of $74,580. 7.5% of residents live below the federal poverty level. Home values sit at a median of $161,200, with monthly rent averaging $881. The homeownership rate of 65.1% is close to the national rate of 64.8%.
Educational attainment in Jefferson County reflects 41.6% of adults 25 and older holding a bachelor's degree or higher, above the national average of 34.3%. Roughly 18.2% of workers primarily work from home, noticeably above the national work-from-home rate of 14.2%. The average commute is 15.2 minutes each way.
Jefferson County Population History (2010-2024)
The county of Jefferson County had a population of 16,835 in 2010 and 15,781 in 2024, a -6.3% growth over 14 years. The peak was 18,180 in 2019. Average annual growth rate: -0.38%.
15,781
Population (2024)
16,835
Population (2010)
18,180
Peak (2019)
-0.38%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 16,835 |
| 2011 | 17,099 |
| 2012 | 17,281 |
| 2013 | 17,632 |
| 2014 | 17,795 |
| 2015 | 17,913 |
| 2016 | 18,027 |
| 2017 | 18,108 |
| 2018 | 18,102 |
| 2019 | 18,180 |
| 2020 | 15,699 |
| 2021 | 15,786 |
| 2022 | 15,632 |
| 2023 | 15,626 |
| 2024 | 15,781 |
Race & Ethnicity
| White | 84.6% |
| Black or African American | 5.9% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 2.1% |
| Two or More Races | 0.0% |
Age & Sex
43.5
Median Age
48.5%
Female
51.5%
Male
25.7%
Age 65+
Age Distribution
Children (under 15): 14.1% · Seniors (65+): 25.7%
Income & Poverty
| Median household income | $56,824$-16,323 vs state |
| Mean household income | $78,591 |
| Per-capita income | $35,800 |
| Poverty rate | 7.5%+0.6% vs state |
| Unemployment rate | 3.2% |
| Employment-to-population | 57.5% |
Top Industries by Employment
The largest employment sector in Jefferson County is professional & business services, accounting for 25.0% of workers.
How residents commute
0.6%
Drive alone
3.6%
Carpool
67.8%
Public transit
18.2%
Work from home
15.2 min
Avg commute
Housing
$161,200$-34,700 vs state
Median home value
$881
Median rent
65.1%
Homeownership rate
7,707
Total housing units
89.2%
Occupied
10.8%
Vacant
34.9%
Renter-occupied
Social & access
92.8%
With health insurance
96.5%
With broadband internet
30.7%
Foreign-born
8.0%
Veterans (18+)
13.7%
With a disability
87.5%
Speak language other than English at home
Education
95.4%
High School+
41.6%
Bachelor's+
Largest cities in Iowa
Other counties in Iowa
Part of Iowa
Metro areas in Iowa
County rankings
Frequently Asked Questions
Jefferson County, Iowa has a population of 15,676 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 48th-largest county in Iowa. Population density is 36 people per square mile.
The population of Jefferson County has declined 6.3% since 2010 (16,835 → 15,781), a -0.46% annualized rate.
The median household income in Jefferson County, Iowa is $56,824, with mean (average) household income of $78,591 and per-capita income of $35,800. 7.5% of residents live below the federal poverty level.
In Jefferson County, the largest racial and ethnic groups are White (84.6%), Black or African American (5.9%), Hispanic or Latino (2.1%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Jefferson County, Iowa is 43.5 years. Residents are 48.5% female and 51.5% male.
The median home value in Jefferson County is $161,200 and median monthly rent is $881. 65.1% of occupied housing units are owner-occupied. The county has 7,707 total housing units, 10.8% of which are vacant.
The largest employment sector in Jefferson County, Iowa is professional, scientific, and management services, employing 25.0% of workers. The unemployment rate is 3.2%.
Des Moines is among the largest cities associated with Jefferson County, Iowa, with a population of 212,464.
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Statewide data for Iowa
Population, race, income, age, and trends across Iowa
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.