Demographics of Gem County, Idaho

Gem County, Idaho had 21,773 people on July 1, 2025, by the Census Bureau’s estimate: +2,498 since July 2020. Age, income, poverty, housing and origin below come from the American Community Survey, averaged over 2020–2024, each with its margin of error.

Gem County, in four figures

21,773
Population: July 1, 2025, Vintage 2025 estimate.; +13.0%
Change since July 2020: +2,498 people.; 44.2 ±0.8
Median age: ACS 2020–⁠2024.; $64,605 ±$6,592
Median household income: ACS 2020–⁠2024, in 2024 dollars.

Population, year by year

July 1 estimates from the Census Bureau’s Vintage 2025. Each year's change is births less deaths, net moves from abroad and net moves from elsewhere in the country, with the Bureau's small residual. The 2020 row's components run 3 months, from the April census to July 1.

Gem County, Idaho's population grew 13.0% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of Gem County, Idaho's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).

U.S. Census Bureau — Census Bureau population estimates — counties and Puerto Rico municipios, with components of change

About this chart

The figures

Gem County, Idaho's population grew 13.0% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of Gem County, Idaho's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).
July 1	Population	Index	United States
2020	19,275	100.0	100.0
2021	19,802	102.7	100.2
2022	20,627	107.0	100.7
2023	21,180	109.9	101.6
2024	21,450	111.3	102.5
2025	21,773	113.0	103.1

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Population of Gem County, Idaho on July 1 of each year, Vintage 2025
July 1	Population	Change	Births less deaths	From abroad	From elsewhere in the country
2020	19,275	+147	−1	0	+161
2021	19,802	+527	−87	+8	+647
2022	20,627	+825	−98	+281	+605
2023	21,180	+553	−31	+188	+389
2024	21,450	+270	−53	+162	+160
2025	21,773	+323	−43	+118	+249

Age, 2020–2024

The median age is 44.2 ±0.8: for men 42.9 ±2.2 and for women 45.0 ±1.0. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in Gem County by age, ACS 2020–2024
Age	People	Share	Idaho	United States
Under 5	1,013 ±85	4.9% ±0.4	5.9% ±<0.1	5.6% ±<0.1
5 to 17	3,510 ±306	17.0% ±1.5	18.2% ±0.2	16.3% ±<0.1
18 to 24	1,427 ±262	6.9% ±1.3	9.8% ±0.1	9.1% ±<0.1
25 to 44	4,666 ±333	22.6% ±1.6	26.1% ±0.2	26.9% ±<0.1
45 to 64	5,243 ±360	25.4% ±1.7	23.0% ±0.2	24.8% ±<0.1
65 and over	4,755 ±396	23.1% ±1.9	17.0% ±0.2	17.2% ±<0.1

Income and poverty, 2020–2024

Median household income is $64,605 ±$6,592, and income per person $33,907 ±$3,301, in 2024 dollars. The median is $77,800 ±$743 in Idaho and $80,734 ±$166 in the United States.

Households by income

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Households in Gem County by income, ACS 2020–2024
Household income	Households	Share	Idaho	United States
Under $25,000	1,056 ±227	13.8% ±2.9	12.5% ±0.3	14.6% ±<0.1
$25,000 to $49,999	1,488 ±307	19.5% ±4.0	17.6% ±0.4	16.7% ±<0.1
$50,000 to $74,999	1,881 ±349	24.6% ±4.5	18.1% ±0.4	15.5% ±<0.1
$75,000 to $99,999	835 ±210	10.9% ±2.7	14.7% ±0.4	12.6% ±<0.1
$100,000 to $149,999	1,475 ±283	19.3% ±3.7	19.3% ±0.4	17.5% ±<0.1
$150,000 to $199,999	374 ±128	4.9% ±1.7	8.7% ±0.3	9.6% ±<0.1
$200,000 or more	534 ±210	7.0% ±2.7	9.2% ±0.3	13.4% ±0.1

Poverty by age

The poverty rate is the share of people whose family income is below the federal threshold for their family’s size, of everyone for whom the Bureau determines it (B17020).

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Poverty rate in Gem County by age, ACS 2020–2024
Age	Below poverty	Rate	Idaho	United States
All ages	2,397 ±526	12.0% ±2.6	10.6% ±0.3	12.5% ±0.1
Under 18	723 ±251	17.4% ±5.8	12.4% ±0.5	16.1% ±0.1
18 to 59	840 ±227	8.9% ±2.4	10.4% ±0.3	11.6% ±0.1
60 and over	834 ±187	13.0% ±2.8	9.1% ±0.4	11.0% ±<0.1

Housing, 2020–2024

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Housing in Gem County, ACS 2020–2024
Measure	Gem County	Idaho	United States
Housing units	7,954 ±21	795,014 ±223	143,775,355 ±10,234
Occupied	96.1% ±2.3	89.7% ±0.3	89.9% ±0.1
Vacant	1.6% to 6.2%	10.3% ±0.3	10.1% ±0.1
Owner occupied	76.0% ±3.3	72.1% ±0.4	65.2% ±0.3
Renter occupied	24.0% ±3.2	27.9% ±0.4	34.8% ±0.1
Median home value	$428,700 ±$33,169	$418,600 ±$2,550	$332,700 ±$236
Median gross rent	$1,038 ±$89	$1,238 ±$16	$1,413 ±$2
Median year built	1983 ±6	1991 ±1	1980 ±1

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Occupied and vacant are shares of all housing units; owner and renter occupied are shares of occupied units. Value and rent are medians in 2024 dollars.

Origin and place of birth, 2020–2024

Hispanic or Latino origin is not a race in the Census Bureau’s tables. Here the people of Hispanic origin, of any race, are one row, and everyone else is counted by race alone (B03002), so the rows add to the whole.

Hispanic origin and race

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People in Gem County by Hispanic origin and race, ACS 2020–2024
Origin	People	Share	Idaho	United States
Hispanic or Latino	1,992 ±0	9.7% ±<0.1	13.6% ±<0.1	19.3% ±<0.1
White alone, not Hispanic	17,211 ±288	83.5% ±1.4	78.6% ±0.1	57.4% ±<0.1
Black alone, not Hispanic	0 to 5	0% to < 0.1%	0.7% ±<0.1	11.9% ±<0.1
Asian alone, not Hispanic	53 to 265	0.3% to 1.3%	1.3% ±<0.1	5.9% ±<0.1
American Indian and Alaska Native alone, not Hispanic	40 to 268	0.2% to 1.3%	0.7% ±<0.1	0.5% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic	0 to 23	0% to 0.1%	0.1% ±<0.1	0.2% ±<0.1
Some other race alone, not Hispanic	22 to 308	0.1% to 1.5%	0.6% ±0.1	0.6% ±<0.1
Two or more races, not Hispanic	931 ±302	4.5% ±1.5	4.2% ±0.1	4.3% ±<0.1

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Place of birth and citizenship

“Born a citizen outside the states” counts people born in Puerto Rico, the island areas, or abroad to American parents. Naturalized citizens and those who are not citizens together make up the people born abroad (B05002).

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People in Gem County by place of birth and citizenship, ACS 2020–2024
Born	People	Share	Idaho	United States
Born in the state	9,306 ±697	45.1% ±3.4	43.9% ±0.3	57.3% ±<0.1
Born in another state	9,938 ±669	48.2% ±3.2	49.1% ±0.3	26.9% ±<0.1
Born a citizen outside the states	11 to 189	0.1% to 0.9%	1.0% ±0.1	1.7% ±<0.1
Born abroad	1,270 ±536	6.2% ±2.6	5.9% ±0.2	14.1% ±<0.1
Naturalized citizens	515 ±201	2.5% ±1.0	2.7% ±0.1	7.4% ±<0.1
Not citizens	357 to 1,153	1.7% to 5.6%	3.2% ±0.2	6.8% ±<0.1

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Gem County among the counties of Idaho

19th of 44 by population, July 2025. Every one is listed on the Idaho page.

Counties of Idaho near Gem County in population, July 2025
County	July 2025	Change since 2020
Payette County	27,824	+8.8%
Cassia County	26,397	+6.6%
Jerome County	26,362	+8.6%
Blaine County	25,517	+4.8%
Minidoka County	22,911	+5.7%
Gem County	21,773	+13.0%
Idaho County	17,874	+7.7%
Gooding County	16,446	+5.1%
Franklin County	15,889	+11.2%
Fremont County	14,208	+5.9%
Shoshone County	14,130	+7.1%

Elsewhere on the site

Sources

Census Bureau population estimates — counties and Puerto Rico municipios, with components of change — U.S. Census Bureau · U.S. Government work · retrieved September 25, 2026
American Community Survey 5-year estimates — table-based Summary File · U.S. Government work

Data retrieved September 25, 2026