99346 ZIP Code — Plymouth, WA

Benton County, Washington

ZIP code 99346 is located in Plymouth, Washington, within Benton County. It covers approximately 142.89 square miles and serves a population of 372 residents. This is a standard ZIP code in the Pacific (PT) timezone, served by area code 509.

About ZIP code 99346

The housing stock consists of a higher-than-average concentration of mobile homes. Most homes were built in the 1970s, giving the area an established character. Median home value is $223,600. Owner-occupancy sits near the national average at 75%.

Median household income is $61,944.

The dominant occupation class is production, transportation, and material moving, with agriculture and mining as the leading industry. The average commute of 20 minutes is near the national average.

Educational attainment is near the national average, with 23% of residents holding a bachelor's degree or higher.

Notable community characteristics include Spanish spoken in 28% of households.

372

population

142.89

sq mi land

Standard

ZIP type

Pacific (PT)

timezone

99346 ZIP code map

Cities in ZIP code 99346

Below are the cities the US Postal Service accepts for ZIP code 99346. Using any city not on this list may result in mail delivery delays.

City	Status
Plymouth	Acceptable

Demographics updated 05/2026

Population
Total population	372
Population density	3 / sq mi
State FIPS	53
County FIPS	005

Geography
Land area	142.89 sq mi
Water area	3.89 sq mi
Latitude	46.0028
Longitude	-119.2890
Timezone	Pacific (PT)
Area code	509

Total population by age

Gender

Race & ethnicity

Economics updated 05/2026

Household income

Income range	This ZIP	County avg	State avg
Under $50k	36.7%	32.9%	31.7%
$50k – $100k	53.3%	33.1%	30.6%
$100k – $200k	10.1%	26.4%	27.1%
Over $200k	0.0%	7.6%	10.6%

Demographics & statistics

372

Population

People per sq mi

28.9

Median age

$61,944

Median household income

$22,928

Per capita income

$223,600

Median home value

$1,000

Median monthly rent

74.6%

Home ownership

17.5%

Poverty rate

20.6%

Unemployment

Housing units

23.4%

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

85+

← Male

Female →

Age summary

Group	Count	%
Under 18	79	21.2%
18 and over	293	78.8%
65 and over	56	15.1%
Median age	28.9 years

Race & ethnicity

Hispanic or Latino 39%

Other race 38.4%

White 21.3%

Two or more races 1.3%

Group	Count	%
Hispanic or Latino	238	39%
Other race	234	38.4%
White	130	21.3%
Two or more races	8	1.3%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	36.7%	32.9%	31.7%
$50k – $100k	53.3%	33.1%	30.6%
$100k – $200k	10.1%	26.4%	27.1%
Over $200k	0.0%	7.6%	10.6%

$10k–$15k 4.4%

$15k–$25k 14.9%

$25k–$35k 7.9%

$35k–$50k 16.7%

$50k–$75k 15.8%

$75k–$100k 19.3%

$100k–$150k 21.1%

Range	% of households
$10k–$15k	4.4%
$15k–$25k	14.9%
$25k–$35k	7.9%
$35k–$50k	16.7%
$50k–$75k	15.8%
$75k–$100k	19.3%
$100k–$150k	21.1%
Median income	$61,944

Housing

Home values

Under $50k 9.4%

$50k–$100k 10.6%

$150k–$200k 10.6%

$200k–$300k 41.2%

$300k–$500k 17.6%

$500k–$1M 4.7%

$1M+ 5.9%

Housing overview

Metric	Value
Median home value	$223,600
Median rent / month	$1,000
Owner occupied	74.6%
Renter occupied	25.4%
Vacant	0.0%
Single-family detached	50.9%
Large apartment buildings	0.0%
Mobile homes	31.6%
Median rooms	5.3
Avg household size (owned)	2.84

Year built

Era	%
2020 or later	0.0%
2010–2019	0.0%
2000–2009	16.7%
1990–1999	27.2%
1980–1989	10.5%
1970–1979	34.2%
1960–1969	11.4%
1950–1959	0.0%
1940–1949	0.0%
1939 or earlier	0.0%

Bedrooms

Size	% of units
No bedroom (studio)	3.5%
1 bedroom	7.0%
2 bedrooms	25.4%
3 bedrooms	28.9%
4 bedrooms	25.4%
5+ bedrooms	9.6%

Vehicles per household

Vehicles	% of households
No vehicle	0.0%
1 vehicle	10.5%
2 vehicles	35.1%
3 or more	54.4%

Heating fuel

Fuel type	%
Electricity	100.0%

Households & families

Household type	Count	%
Married-couple family	43	37.7%
Cohabiting couple	9	7.9%
Male householder, no spouse	36	31.6%
Female householder, no spouse	26	22.8%
Households with children under 18	36	31.6%
Households with seniors (65+)	34	29.8%
Average household size	3.17

Marital status

Status	Male	Female
Never married	46.8%	48.0%
Married	42.7%	30.6%
Separated	0.0%	5.2%
Widowed	4.0%	1.7%
Divorced	6.5%	14.5%

Education

Less than 9th grade 12.8%

Some HS, no diploma 7.8%

HS graduate 24.8%

Some college, no degree 20.2%

Associate's degree 11.0%

Bachelor's degree 23.4%

Graduate / professional 0.0%

Metric	%
HS diploma or higher	79.4%
Bachelor's or higher	23.4%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	0	0.0%
Kindergarten	10	13.0%
Elementary school	37	48.1%
High school	16	20.8%
College / grad school	14	18.2%

Employment

Industry of employment

Agriculture & mining 18.5%

Manufacturing 17.0%

Wholesale trade 17.0%

Transportation & utilities 15.6%

Education & healthcare 9.6%

Arts, food & hospitality 8.9%

Retail trade 7.4%

Finance & real estate 3.0%

Public administration 3.0%

Occupation

Category	%
Management, business & arts	17.8%
Service	18.5%
Sales & office	14.1%
Natural resources & construction	19.3%
Production & transportation	30.4%

Employment type

Type	%
Private sector	88.9%
Government	11.1%
Self-employed	0.0%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	65.9%
Carpool	23.0%
Public transit	0.0%
Walk	0.0%
Work from home	11.1%
Other means	0.0%
Avg commute (minutes)	19.7

Poverty

All people 17.5%

Under 18 years 48.1%

18 and over 9.2%

Married-couple families 0.0%

Female-led households 25.7%

Income support

Source	% of households
Social Security	29.8%
Retirement income	7.9%
Supplemental Security	14.0%
Cash public assistance	0.0%
Food stamps / SNAP	16.7%

Health indicators

Condition	%
Obesity	36.3%
High blood pressure	32.1%
High cholesterol	35.6%
Diabetes	11.0%
Heart disease	6.5%
Stroke	3.0%
Asthma	10.9%
Arthritis	25.7%
Kidney disease	3.0%
Pulmonary disease	7.1%
Cancer	6.3%

Behavior / access	%
Smoking	16.9%
Binge drinking	15.7%
No physical activity	23.3%
Less than 7 hrs sleep	30.9%
Depression	26.4%
Fair or poor health	17.6%
Poor mental health	15.3%
Poor physical health	12.5%
No health insurance	18.4%
Visited doctor (checkup)	70.7%
Visited dentist	61.7%
Cholesterol screening	87.9%
Teeth loss	13.0%

Veterans & disability

Veterans	Count	%
Civilian veterans	21	7.2%

Disability	%
Any disability	9.9%
Under 18	6.3%
18–64 years	3.4%
65 and over	42.9%

Health insurance coverage

Type	%
Private insurance	65.1%
Public insurance	43.8%
No insurance	9.9%
Uninsured under 19	12.4%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	344	92.5%
Spanish	95	27.6%
Other Indo-European	95	27.6%
Asian & Pacific Islander	0	0.0%
Other languages	0	0.0%

Place of birth & citizenship

Origin	Count	%
Native born (US)	262	70.4%
Born in same state	262	70.4%
Born in different state	122	32.8%
Foreign born	0	0.0%
Naturalized citizen	110	29.6%
Not a US citizen	66	60.0%

Ancestry

Ancestry	Count	%
French	38	10.2%
Italian	29	7.8%

Ancestry	Count	%
Dutch	13	3.5%
Arab	8	2.2%

Technology access

Metric	% of households
Computer access	30.6%
Internet access	95.6%

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

Frequently asked questions about ZIP code 99346

What city is ZIP code 99346 in?

ZIP code 99346 is primarily assigned to Plymouth, Washington.

What county is ZIP code 99346 in?

ZIP code 99346 falls within Benton County, Washington.

Is Spanish widely spoken in ZIP code 99346?

Approximately 28% of households in ZIP code 99346 speak Spanish as a primary language.

What is the poverty rate in ZIP code 99346?

18% of residents in ZIP code 99346 live below the poverty line, above the national average.

What is the population of ZIP code 99346?

ZIP code 99346 has an estimated population of 372 residents, with a density of 3 people per square mile.

What is the median household income in ZIP code 99346?

The median household income in ZIP code 99346 is $61,944, below the national median of ~$75,000.

What timezone is ZIP code 99346 in?

ZIP code 99346 observes the PST timezone.