Gem County, Idaho Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 19th-largest in Idaho
The population of Gem County, Idaho is 19,854 as of the 2023 American Community Survey, making it the 19th-largest county in Idaho. The median household income is $66,245, the median home value is $367,300, and the median age is 42.8.
The population of Gem County has grown 31.0% since 2010 (16,686 → 21,857), a +1.95% annualized rate.
19,854
Population
+1.95%
Annual growth
35
People / sq mi
$66,245
Median Income
$367,300
Median Home Value
Gem County covers 560 sq mi of land at 35.5 people per square mile.
About Gem County, ID
Gem County is distinguished by its share of foreign-born residents, 49.3% of the population. With 19,854 residents, Gem County is a county in Idaho. It ranks #19 among counties in Idaho by population.
The typical household here earns about $66,245, below the US median of $78,538. Only 6.9% of residents live in poverty, below the national 12.4%. Home prices are steep, with the typical property valued at $367,300, with typical rent around $887.
Roughly 22.3% of adults have a bachelor’s, below the national 35.0%. About 12.6% of workers primarily work from home, below the national 14.0%, and the average commute runs about 31 minutes each way.
The large foreign-born share is a defining thread in Gem County, shaping language, household composition, and the labor force behind the economic figures above.
Gem County Population History (2010-2024)
The county of Gem County had a population of 16,686 in 2010 and 21,857 in 2024, a 31.0% growth over 14 years. The peak was 21,857 in 2024. Average annual growth rate: 1.96%.
21,857
Population (2024)
16,686
Population (2010)
21,857
Peak (2024)
1.96%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 16,686 |
| 2011 | 16,696 |
| 2012 | 16,638 |
| 2013 | 16,582 |
| 2014 | 16,665 |
| 2015 | 16,706 |
| 2016 | 17,005 |
| 2017 | 17,351 |
| 2018 | 17,622 |
| 2019 | 18,174 |
| 2020 | 19,278 |
| 2021 | 19,813 |
| 2022 | 20,739 |
| 2023 | 21,384 |
| 2024 | 21,857 |
Race & Ethnicity
| White | 87.2% |
| Black or African American | 0.2% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 2.0% |
| Two or More Races | 0.0% |
Age & Sex
42.8
Median Age
49.1%
Female
50.9%
Male
22.7%
Age 65+
Age Distribution
Children (under 15): 18.4% · Seniors (65+): 22.7%
Income & Poverty
| Median household income | $66,245$-8,391 vs state |
| Mean household income | $87,429 |
| Per-capita income | $34,695 |
| Poverty rate | 6.9%-0.1% vs state |
| Unemployment rate | 1.6% |
| Employment-to-population | 55.6% |
Top Industries by Employment
The largest employment sector in Gem County is professional & business services, accounting for 21.5% of workers.
How residents commute
0.2%
Drive alone
1.4%
Carpool
75.3%
Public transit
12.6%
Work from home
30.9 min
Avg commute
Housing
$367,300$-8,700 vs state
Median home value
$887
Median rent
76.6%
Homeownership rate
7,788
Total housing units
95.1%
Occupied
4.9%
Vacant
23.4%
Renter-occupied
Social & access
88.1%
With health insurance
93.1%
With broadband internet
49.3%
Foreign-born
9.5%
Veterans (18+)
17.7%
With a disability
90.8%
Speak language other than English at home
Education
89.0%
High School+
22.3%
Bachelor's+
Largest cities in Idaho
Other counties in Idaho
Part of Idaho
Metro areas in Idaho
County rankings
Frequently Asked Questions
Gem County, Idaho has a population of 19,854 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 19th-largest county in Idaho. Population density is 35 people per square mile.
The population of Gem County has grown 31.0% since 2010 (16,686 → 21,857), a +1.95% annualized rate.
The median household income in Gem County, Idaho is $66,245, with mean (average) household income of $87,429 and per-capita income of $34,695. 6.9% of residents live below the federal poverty level.
In Gem County, the largest racial and ethnic groups are White (87.2%), Hispanic or Latino (2.0%), Black or African American (0.2%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Gem County, Idaho is 42.8 years. Residents are 49.1% female and 50.9% male.
The median home value in Gem County is $367,300 and median monthly rent is $887. 76.6% of occupied housing units are owner-occupied. The county has 7,788 total housing units, 4.9% of which are vacant.
The largest employment sector in Gem County, Idaho is professional, scientific, and management services, employing 21.5% of workers. The unemployment rate is 1.6%.
Boise City is among the largest cities associated with Gem County, Idaho, with a population of 235,701.
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Statewide data for Idaho
Population, race, income, age, and trends across Idaho
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.