| City: | Plymouth, Washington |
| County: | Benton County |
| Timezone: | Pacific (GMT -08:00) |
| Local Time: | 12:18:53 AM |
| Population: | 345 [See All] |
| Area Code: | 509 |
| Classification: | PO Box |
| Coordinates: | 46.0028, -119.2890 |
| Land Area: | 142.889 sq mi |
| Quick Link: |
Plymouth is a small rural community in southeastern Washington's Benton County, where 345 residents are spread across 81 square miles of farmland and desert terrain. This is a PO Box Only Zone. There's no carrier delivery to street addresses. The post office maintains 163 PO Boxes for 157 households, with virtually everyone relying on boxes for mail service.
The community is served by two rural carrier routes covering 66 delivery points scattered across the territory. Street names like E Christy Rd (15 addresses), S Plymouth Rd (7 addresses), and E Blue Sky Pr SE hint at the spread-out character of this agricultural area. The numbered grid streets (E 3rd Ave, E 1st St) suggest a historic town center, though most addresses are on rural roads and private routes.
With a median age of 46.8 years and median household income of $50,588, Plymouth has a working-age population. Transportation and warehousing dominate the local economy, accounting for the employment of 85 workers. That's unusual for such a small community and likely reflects Plymouth's position along transportation corridors in agricultural Benton County. An additional 25% of workers (28 people) work from home, suggesting remote work or farm-based livelihoods.
Housing is modest and established. The median home value stands at $214,700, with 81% of occupied homes owner-occupied (127 of 157 households). Roughly half of structures (88 of 176 total housing units) were built before 1939, indicating Plymouth's longevity as a settlement. Only 19 homes sit vacant, a 11% vacancy rate that's typical for year-round rural communities.
Primary City Name: Plymouth, WA 99346
PO Box Requirement: This is a PO Box Only Delivery Zone. Mail must be addressed to a PO Box at the Plymouth post office. Street addresses are not valid for mail delivery.
Street names mix rural roads (Christy Rd, Plymouth Rd) with numbered streets (1st, 2nd, 3rd) that hint at a historic town core, plus scattered private routes across the territory.
ZIP Code 99346 has 345 residents and 157 households (average 2.20 persons per household). The median age is 46.8 years, significantly older than the state (38.1) and significantly older than the nation (38.8). The gender split is 52.2% male and 47.8% female, which is higher than the national male share (49.1%), making this a male-majority area. Largest groups are White (67.2%, higher than the national average of 61.6%) and Hispanic or Latino (40.6%); Hispanic or Latino residents make up 40.6%, which is much higher than the state average (13.7%).
Explore More:Population Over TimeBy Age & GenderBy RaceBy GenderNativity & Citizenship
| 2020 Population: | 345Source: Census DHC |
| 2024 ACS Population Estimate: | 269Source: Census ACS |
| 2026 ZC Population Estimate: | 0Source: ZIP-Codes.com |
| Population Density: | 2.4 people per sq mile |
| Average Income: | $50,588Source: Census ACS |
| Households: | 157Source: Census DHC |
| Average House Value: | $214,700Source: Census ACS |
| Persons Per Household: | 2.20Source: Census DHC |
| Average Family Size: | 3.18Source: Census ACS |
| Group | 2010 | 2011 | 2102 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Census ACS Population Estimate | -- | 329 | 401 | 545 | 367 | 436 | 457 | 442 | 466 | 548 | 443 | 337 | 372 | 269 |
| Decennial Census | 352 | -- | -- | -- | -- | -- | -- | -- | -- | -- | 345 | -- | -- | -- |
Median Age: 46.8
Male Median Age: 45.5
Female Median Age: 47.5
| Group | < 5 | 5-9 | 10-14 | 15-19 | 20-24 | 25-29 | 30-34 | 35-39 | 40-44 | 45-49 | 50-54 | 55-59 | 60-64 | 65-69 | 70-74 | 75-79 | 80-84 | 85+ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Male | 4 | 11 | 13 | 8 | 5 | 9 | 15 | 13 | 11 | 7 | 11 | 17 | 16 | 15 | 7 | 6 | 9 | 3 |
| Female | 16 | 11 | 6 | 8 | 6 | 5 | 7 | 8 | 12 | 11 | 10 | 22 | 17 | 7 | 12 | 4 | 3 | 0 |
| Total | 20 | 22 | 19 | 16 | 11 | 14 | 22 | 21 | 23 | 18 | 21 | 39 | 33 | 22 | 19 | 10 | 12 | 3 |
| White: | 232 | 53.70% |
| Black: | 0 | 0% |
| Hispanic:* | 140 | 32.41% |
| Asian: | 1 | 0.23% |
| American Indian: | 2 | 0.46% |
| Hawaiian: | 0 | 0% |
| Other: | 57 | 13.19% |
| Total: | 432 | 100% |
| Gender | Count | % | Median Age |
|---|---|---|---|
| Males: | 180 | 52.17% | 45.5 years |
| Females: | 165 | 47.83% | 47.5 years |
| Total: | 345 | 100% | 46.8 years |
| Native, born in the United States: | 224 | 83.27% |
| Native, born in PR, Island Areas, or abroad: | 0 | 0.00% |
| Foreign born, naturalized U.S. citizen: | 26 | 9.67% |
| Foreign born, not a U.S. citizen: | 19 | 16.73% |
| Total Population: | 269 | 100% |
| Total Native Population: | 224 | 83.27% |
| Total Foreign-born Population: | 45 | 16.73% |
In 2023, the Median household income is $50,588, which is far less than the state median ($94,952), is up $20,796 (69.8%) since 2011 and below its 2019 pre-pandemic level by $13,891. Family households earn a median of $0 versus $38,333 for nonfamily households (a difference of $38,333). By gender, male median income is $34,688 and female is $0, which is well under the state female median ($63,283), with a current gap of $34,688 that has widened from 2011 to 2023. The labor-force participation rate is 43.9%, which is markedly below the state rate (64.7%). The unemployment rate is 0.0%, which is markedly below the national rate (5.2%). The largest occupation group is Production (45.2%).
Explore More:Income Over TimeHousehold IncomeEmployment StatusBy Occupation
| Income Type | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Median Household Income | $29,792 | $29,224 | $31,676 | $34,659 | $41,917 | $62,273 | $61,750 | $67,850 | $64,479 | $63,229 | $65,250 | $61,944 | $50,588 |
| Median Family Income | $29,292 | $29,353 | $35,417 | $70,962 | $79,063 | $75,000 | $73,438 | $76,731 | $71,083 | $68,750 | $73,542 | $49,318 | $0 |
| Median NonFamily Income | $31,667 | $21,563 | $23,750 | $16,442 | $32,917 | $28,167 | $24,808 | $23,854 | $26,333 | $0 | $0 | $0 | $38,333 |
| Median Male Income | $0 | $30,938 | $35,542 | $36,466 | $36,923 | $36,806 | $41,477 | $53,750 | $47,500 | $53,929 | $42,159 | $40,156 | $34,688 |
| Median Female Income | $0 | $0 | $16,688 | $50,673 | $46,250 | $46,354 | $47,292 | $43,523 | $42,885 | $0 | $45,682 | $0 | $0 |
| Employed: | 93 | 43.87% |
| Unemployed: | 0 | 0.00% |
| Not In Labor Force: | 119 | 56.13% |
| Total: | 212 | 100% |
| Management, business, science, and arts: | 8 | 8.60% |
| Service: | 0 | 0.00% |
| Sales and Office: | 24 | 25.81% |
| Natural resources, construction, and maintenance: | 19 | 20.43% |
| Production, transportation, and material moving: | 42 | 45.16% |
| Total Civilian Employed Population: | 93 | 100% |
In 2023, the median home value is $214,700, which is far less than the state median ($519,800), is up $196,400 (1,073.22%) since 2011 and above its 2019 pre-pandemic level by $31,200. The median gross rent is $0, which is far less than the state median ($1,682), and below its 2019 pre-pandemic level by $827. Of occupied housing, owners make up 68.18% (21.67% with a mortgage, 78.33% free-and-clear) and renters 31.82% - making this ZIP Code more home ownership than the state and under national rental averages. Insufficient data for vacancy rate.
Explore More:Compare Home ValueHome Value Over TimeRent & Over TimeHousing Occupancy
| Group | 2011 | 2102 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Median Home Value | $18,300 | $18,400 | $17,200 | $29,000 | $118,300 | $176,900 | $173,600 | $182,700 | $183,500 | $190,900 | $171,000 | $223,600 | $214,700 |
| Less than $500: | 0 | 0.00% |
| $500 to $999: | 0 | 0.00% |
| $1,000 to $1,499: | 28 | 100.00% |
| $1,500 to $1,999: | 0 | 0.00% |
| $2,000 to $2,499: | 0 | 0.00% |
| $2,500 to $2,999: | 0 | 0.00% |
| $3,000 or more: | 0 | 0.00% |
| No Rent: | 0 | 0.00% |
| Total: | 28 | 100% |
| Group | 2011 | 2102 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Median Rent | $0 | $764 | $773 | $773 | $693 | $673 | $0 | $0 | $827 | $0 | $0 | $1,000 | $0 |
| Owner Occupied (with mortgage): | 13 | 14.77% |
| Owner Occupied (free and clear, no mortgage): | 47 | 53.41% |
| Renter Occupied: | 28 | 31.82% |
| Total Occupied Housing Units: | 88 | 100% |
| Occupied Housing Units: | 88 | 100.00% |
| Vacant Housing Units (not graphed): | 0 | 0.00% |
| Total Housing Units: | 88 | 100% |
| Single-Family Units: | 39 | 44.32% |
| Multi-Family Units: | 14 | 15.91% |
| Other Units: | 35 | 39.77% |
| Total Housing Units: | 88 | 100% |
In 2023, 32.30% of adults (25+) have a bachelor's degree or higher, which is on par with the state rate (38.80%). High school or higher is 88.00%, which is on par with the state rate (92.20%). The uninsured rate is 5.20%, which is comparable to the national rate (8.60%). Public coverage is 58.40%, which is markedly above the state rate (35.80%). The share of people in poverty is 18.50%, which is on par with the state rate (6.40%), down 51.30 percentage points since 2011 and above its 2019 pre-pandemic level by 16.20 percentage points. This points to a pronounced improvement in local conditions - rising incomes, firmer consumer demand, and a stronger tax base. Among residents ages 3+, the largest enrollment group is elementary (76.00%). College enrollment is 0.00%, which is comparable to the national rate (26.70%), meaning the community mirrors broader higher-education participation.
Explore More:Educational AttainmentHealth InsurancePoverty Over TimeSchool Enrollment
| Less than 9th grade: | 15 | 8.98% |
| 9th to 12th grade, no diploma: | 5 | 2.99% |
| High school graduate (includes equivalency): | 56 | 33.53% |
| Some college, no degree: | 20 | 11.98% |
| Associate's degree: | 17 | 10.18% |
| Bachelor's degree: | 49 | 29.34% |
| Graduate or professional degree: | 5 | 2.99% |
| Total: | 167 | 100% |
| High school or higher: | 147 | 88.02% |
| Bachelor's degree or higher: | 54 | 32.34% |
| Private Insurance: | 170 | 49.85% |
| Public Insurance: | 157 | 46.04% |
| No Insurance: | 14 | 4.11% |
| Total: | 341 | 100% |
| Has Health Insurance: | 327 | 95.89% |
| Group | 2011 | 2102 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| % of People in Poverty | 69.8% | 54.7% | 38.7% | 0.0% | 0.0% | 0.0% | 0.0% | 0.0% | 2.3% | 5.0% | 3.9% | 11.5% | 18.5% |
Note: Counts of Families & People in poverty are not published at the ZIP Code level due to small sample sizes. Percentages shown are survey estimates from the American Community Survey (ACS). They may differ from official poverty statistics. The U.S. Census Bureau defines poverty status by comparing a family's or individual's total income with federal poverty thresholds that vary by family size and composition.
| Nursery School, Preschool: | 0 | 0.00% |
| Kindergarten: | 0 | 0.00% |
| Elementary school (grades 1-8): | 19 | 76.00% |
| High school (grades 9-12): | 6 | 24.00% |
| College or graduate school: | 0 | 0.00% |
| Total: | 25 | 100% |
| Early Childhood: | 0 | 0.00% |
| K-12 (Primary & Secondary School): | 25 | 100.00% |
ZIP Code 99346 supports both business and residential activity. According to the Business Census (2024), there are 7 business establishments, employing about 114 people with an annual payroll of $11,186,000.
| # Residential Mailboxes: | 0Source: USPS |
| # Business Mailboxes: | 0Source: USPS |
| Total Delivery Receptacles: | 170Source: USPS |
| Single Family Delivery Units: | 0Source: USPS |
| Multi Family Delivery Units: | 0Source: USPS |
| # of Businesses: | 7Source: CBP |
| 1st Quarter Payroll: | $2,885,000Source: CBP |
| Annual Payroll: | $11,186,000Source: CBP |
| # of Employees: | 114Source: CBP |
ZIP Code 99346 is located in Benton County, Washington, within the Kennewick-Richland, WA Metropolitan Statistical Area (CBSA 28420) and Washington's 4th Congressional District. This Metro area has a population of 307,900 people, about 0.11% of whom live in ZIP Code 99346. It covers 142.889 sq mi of land and a water area of 3.894 sq mi.
| CBSA Name: | Kennewick-Richland, WASource: Census |
| CBSA Number: | 28420Source: Census |
| CBSA Type: | MetroSource: Census |
| CBSA Division: | --Source: Census |
| CBSA Population: | 307,900Source: Census |
| MSA: | Richland-Kennewick-Pasco, WA MSASource: Census |
| Land Area: | 142.889 sq miSource: Census |
| Water Area: | 3.894 sq miSource: Census |
| Congressional District: | 04Source: USPS |
| Congressional Land Area: | 19250.22 sq miSource: Census |
| PMSA: | --Source: Census |
| Intro Date: | < 2004-10Source: ZIP-Codes.com |
| Place FIPS Code: | --Source: Census |
| Place Name: | --Source: Census |
We could not locate which school district 99346 belongs to, but we will update this once new district data is released. There are no public schools nor private schools with a mailing address in this ZIP Code. Listing Nearby schools instead. It also has 6 colleges, universities or post secondary education institutions nearby which would be a short commute to.
Our sources include trusted federal and licensed data from the United States Postal Service, U.S. Census Bureau, U.S. Geological Survey, Centers for Medicare & Medicaid Services, and the National Center for Education Statistics, along with proprietary datasets created by ZIP-Codes.com. Data last updated on January 1, 2026.