83321 ZIP Code — Castleford, ID

Twin Falls County, Idaho

ZIP code 83321 is located in Castleford, Idaho, within Twin Falls County. It covers approximately 181.18 square miles and serves a population of 496 residents. This is a standard ZIP code in the Mountain (MT) timezone, served by area code 208.

About ZIP code 83321

The housing stock consists of predominantly single-family detached homes. Most homes were built in the 1970s, giving the area an established character. Median home value is $266,700. Owner-occupancy sits near the national average at 71%.

Median household income is $52,262. 43% of households receive Social Security income, suggesting a notable retiree or disability population.

The dominant occupation class is management, business, and professional, with agriculture and mining as the leading industry. The average commute of 22 minutes is near the national average.

Educational attainment is near the national average, with 32% of residents holding a bachelor's degree or higher.

496

population

181.18

sq mi land

Standard

ZIP type

Mountain (MT)

timezone

83321 ZIP code map

Cities in ZIP code 83321

Below are the cities the US Postal Service accepts for ZIP code 83321. Using any city not on this list may result in mail delivery delays.

City	Status
Castleford	Acceptable
Castleford	Preferred

Nearby ZIP codes

83316 Buhl (10.9 mi) 83301 Twin Falls (14.5 mi) 83328 Filer (17 mi)

Demographics updated 08/2026

Population
Total population	496
Population density	3 / sq mi
State FIPS	16
County FIPS	083

Geography
Land area	181.18 sq mi
Water area	0.14 sq mi
Latitude	42.4341
Longitude	-114.8914
Timezone	Mountain (MT)
Area code	208

Total population by age

Gender

Race & ethnicity

Economics updated 08/2026

Household income

Income range	This ZIP	County avg	State avg
Under $50k	57.2%	45.7%	41.8%
$50k – $100k	14.8%	34.7%	34.0%
$100k – $200k	27.9%	16.5%	19.5%
Over $200k	0.0%	3.0%	4.7%

Demographics & statistics

496

Population

People per sq mi

39.8

Median age

$52,262

Median household income

$25,717

Per capita income

$266,700

Median home value

$1,045

Median monthly rent

70.5%

Home ownership

10.5%

Poverty rate

5.1%

Unemployment

166

Housing units

31.5%

Bachelor's or higher

Age distribution

Male Female

Under 5

5–9

10–14

15–19

20–24

25–34

35–44

45–54

55–59

60–64

65–74

75–84

85+

← Male

Female →

Age summary

Group	Count	%
Under 18	123	24.8%
18 and over	373	75.2%
65 and over	129	26.0%
Median age	39.8 years

Race & ethnicity

White 55.8%

Hispanic or Latino 19.3%

Two or more races 17.6%

Other race 6.5%

American Indian / Alaska Native 0.8%

Group	Count	%
White	343	55.8%
Hispanic or Latino	119	19.3%
Two or more races	108	17.6%
Other race	40	6.5%
American Indian / Alaska Native	5	0.8%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	57.2%	45.7%	41.8%
$50k – $100k	14.8%	34.7%	34.0%
$100k – $200k	27.9%	16.5%	19.5%
Over $200k	0.0%	3.0%	4.7%

Under $10k 3.8%

$10k–$15k 1.0%

$15k–$25k 6.7%

$25k–$35k 8.6%

$35k–$50k 21.0%

$50k–$75k 31.4%

$75k–$100k 12.4%

$100k–$150k 9.0%

$150k–$200k 4.8%

$200k+ 1.4%

Range	% of households
Under $10k	3.8%
$10k–$15k	1.0%
$15k–$25k	6.7%
$25k–$35k	8.6%
$35k–$50k	21.0%
$50k–$75k	31.4%
$75k–$100k	12.4%
$100k–$150k	9.0%
$150k–$200k	4.8%
$200k+	1.4%
Median income	$52,262

Housing

Home values

Under $50k 12.2%

$50k–$100k 7.4%

$100k–$150k 4.7%

$150k–$200k 20.9%

$200k–$300k 6.1%

$300k–$500k 39.2%

$500k–$1M 8.1%

$1M+ 1.4%

Housing overview

Metric	Value
Median home value	$266,700
Median rent / month	$1,045
Owner occupied	70.5%
Renter occupied	29.5%
Vacant	7.9%
Single-family detached	80.3%
Large apartment buildings	0.0%
Mobile homes	19.7%
Median rooms	5.9
Avg household size (owned)	2.16

Year built

Era	%
2020 or later	0.0%
2010–2019	3.1%
2000–2009	20.6%
1990–1999	14.9%
1980–1989	12.7%
1970–1979	27.6%
1960–1969	3.1%
1950–1959	1.3%
1940–1949	8.8%
1939 or earlier	7.9%

Bedrooms

Size	% of units
No bedroom (studio)	0.9%
1 bedroom	4.8%
2 bedrooms	24.6%
3 bedrooms	52.2%
4 bedrooms	13.2%
5+ bedrooms	4.4%

Vehicles per household

Vehicles	% of households
No vehicle	1.9%
1 vehicle	11.0%
2 vehicles	20.0%
3 or more	67.1%

Heating fuel

Fuel type	%
Electricity	71.0%
Propane / LP gas	5.7%
Fuel oil	12.4%
Wood	7.6%

Households & families

Household type	Count	%
Married-couple family	146	69.5%
Cohabiting couple	4	1.9%
Male householder, no spouse	23	11.0%
Female householder, no spouse	37	17.6%
Households with children under 18	66	31.4%
Households with seniors (65+)	91	43.3%
Average household size	2.36

Marital status

Status	Male	Female
Never married	27.6%	10.4%
Married	70.6%	60.4%
Separated	0.9%	1.2%
Widowed	0.0%	11.6%
Divorced	0.9%	16.5%

Education

Less than 9th grade 9.3%

Some HS, no diploma 7.3%

HS graduate 28.7%

Some college, no degree 16.9%

Associate's degree 6.5%

Bachelor's degree 22.5%

Graduate / professional 9.0%

Metric	%
HS diploma or higher	83.4%
Bachelor's or higher	31.5%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	9	9.2%
Kindergarten	0	0.0%
Elementary school	68	69.4%
High school	16	16.3%
College / grad school	5	5.1%

Employment

Industry of employment

Agriculture & mining 29.8%

Manufacturing 19.0%

Education & healthcare 19.0%

Professional & management 9.8%

Arts, food & hospitality 5.4%

Transportation & utilities 4.4%

Retail trade 2.9%

Wholesale trade 2.4%

Information 2.0%

Finance & real estate 2.0%

Other services 1.5%

Public administration 1.5%

Construction 0.5%

Occupation

Category	%
Management, business & arts	28.8%
Service	8.3%
Sales & office	16.1%
Natural resources & construction	20.0%
Production & transportation	26.8%

Employment type

Type	%
Private sector	84.4%
Government	10.2%
Self-employed	5.4%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	88.8%
Carpool	0.5%
Public transit	0.0%
Walk	0.5%
Work from home	8.8%
Other means	1.5%
Avg commute (minutes)	22.4

Poverty

All people 10.5%

Under 18 years 13.0%

18 and over 9.7%

Married-couple families 4.8%

Female-led households 23.1%

Income support

Source	% of households
Social Security	43.3%
Retirement income	30.0%
Supplemental Security	8.1%
Cash public assistance	0.0%
Food stamps / SNAP	5.2%

Health indicators

Condition	%
Obesity	32.4%
High blood pressure	29.4%
High cholesterol	27.7%
Diabetes	9.3%
Heart disease	6.0%
Stroke	2.8%
Asthma	9.1%
Arthritis	21.7%
Kidney disease	2.8%
Pulmonary disease	5.8%
Cancer	6.2%

Behavior / access	%
Smoking	15.1%
Binge drinking	14.6%
No physical activity	21.4%
Less than 7 hrs sleep	31.4%
Depression	19.4%
Fair or poor health	13.1%
Poor mental health	12.8%
Poor physical health	10.1%
No health insurance	21.3%
Visited doctor (checkup)	69.1%
Visited dentist	65.1%
Cholesterol screening	85.9%
Teeth loss	13.8%

Veterans & disability

Veterans	Count	%
Civilian veterans	24	6.4%

Disability	%
Any disability	15.7%
Under 18	12.2%
18–64 years	10.7%
65 and over	28.7%

Health insurance coverage

Type	%
Private insurance	73.4%
Public insurance	43.1%
No insurance	8.5%
Uninsured under 19	17.2%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	449	90.5%
Spanish	43	9.6%
Other Indo-European	43	9.6%
Asian & Pacific Islander	0	0.0%
Other languages	0	0.0%

Place of birth & citizenship

Origin	Count	%
Native born (US)	456	91.9%
Born in same state	456	91.9%
Born in different state	334	67.3%
Foreign born	0	0.0%
Naturalized citizen	40	8.1%
Not a US citizen	25	62.5%

Ancestry

Ancestry	Count	%
French	52	10.5%
Italian	27	5.4%
Arab	21	4.2%

Ancestry	Count	%
English	11	2.2%
Irish	5	1%
Dutch	2	0.4%

Technology access

Metric	% of households
Computer access	42.3%
Internet access	94.3%

Source: U.S. Census Bureau, American Community Survey 2025 estimates.

Frequently asked questions about ZIP code 83321

What city is ZIP code 83321 in?

ZIP code 83321 is primarily assigned to Castleford, Idaho.

What county is ZIP code 83321 in?

ZIP code 83321 falls within Twin Falls County, Idaho.

Does ZIP code 83321 have an older population?

26% of residents in ZIP code 83321 are 65 or older, above the national average of ~17%.

Does ZIP code 83321 have a large retiree population?

43% of households in ZIP code 83321 receive Social Security income, suggesting a significant retiree or disability population.

What is the population of ZIP code 83321?

ZIP code 83321 has an estimated population of 496 residents, with a density of 3 people per square mile.

What is the median household income in ZIP code 83321?

The median household income in ZIP code 83321 is $52,262, below the national median of ~$75,000.

What timezone is ZIP code 83321 in?

ZIP code 83321 observes the MST timezone.