91789 ZIP Code, Walnut, CA
91789 is a ZIP code in Walnut, California in Los Angeles County. It covers 16 square miles of land. The closest ZIP codes are 91792, 91765 and 91791. 40,298 people live here in 12,681 households. At about 2,540 people per square mile it has suburban density, and most homes are owner-occupied (82%). Median household income is $125,720, above the California median of $99,122; the median age is 46.3, older than most ZIP codes.
Quick facts
- Mailing city: Walnut, CA
- County: Los Angeles County
- Land area: 16 sq mi
- Population: 40,298
- Median household income: $125,720
- Carrier routes: 31 (13,516 homes)
Key figures
| Measure | Value |
|---|---|
| Residents | 40,298 |
| Households | 12,681 |
| Median household income | $125,720 |
| Income per person | $49,392 |
| Median age | 46.3 |
| Homeowners | 82.1% |
| Median home value | $975,000 |
| Median rent | $2,865 |
| Bachelor's degree or higher | 54.4% |
| Average commute (minutes) | 33.5 |
| Households with kids under 18 | 31.8% |
| Moved in the past year | 8.7% |
| Below the poverty line | 9.2% |
| Broadband internet | 96.3% |
| Speak a non-English language at home | 67.8% |
Household income
| % of households | Value |
|---|---|
| <$10K | 4.9% |
| $10–15K | 1.3% |
| $15–25K | 2.4% |
| $25–35K | 4.7% |
| $35–50K | 6.0% |
| $50–75K | 10.0% |
| $75–100K | 9.7% |
| $100–150K | 20.7% |
| $150–200K | 14.8% |
| $200K+ | 25.5% |
Age
| % of all residents | Value |
|---|---|
| <10 | 9.8% |
| 10–19 | 11.9% |
| 20–24 | 4.8% |
| 25–34 | 11.2% |
| 35–44 | 10.8% |
| 45–54 | 12.6% |
| 55–64 | 16.6% |
| 65–74 | 14.9% |
| 75+ | 7.4% |
Tenure
| % of housing units | Value |
|---|---|
| Owned, with mortgage | 46.5% |
| Owned outright | 30.9% |
| Rented | 16.6% |
| Vacant | 6.0% |
Type of building
| % of housing units | Value |
|---|---|
| Detached house | 86.5% |
| Townhome | 5.1% |
| 2–4 units | 2.2% |
| 5–19 units | 0.6% |
| 20+ units | 1.8% |
| Mobile / other | 3.9% |
Businesses in 91789
2,325 business establishments with 21,957 employees (ZIP Codes Business Patterns 2023).
- Wholesale Trade: 513
- Professional, Scientific, and Technical Services: 292
- Transportation and Warehousing: 249
- Retail Trade: 230
- Health Care and Social Assistance: 173
- Real Estate and Rental and Leasing: 152
- Other Services (except Public Administration): 131
- Accommodation and Food Services: 127
EDDM carrier routes
91789 has 31 USPS carrier routes with 13,516 residential and 1,791 business mailboxes. Open the EDDM route map.
Carrier routes in 91789
91789 has 31 USPS carrier routes (31 city (C)) with 13,516 residential and 1,791 business mailboxes. Routes range from 137 homes (C029) to 677 homes (C034); the median route has 480 homes. The Census counted 12,681 households in 91789 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.
| Homes per route | Routes |
|---|---|
| 1–249 | 5 |
| 250–499 | 12 |
| 500–749 | 14 |
| 750–999 | 0 |
| 1,000–1,499 | 0 |
| 1,500+ | 0 |
Best routes in 91789 for…
Most businesses
For B2B offers: office supplies, cleaning, IT, catering and commercial services.
- Route C025 — USPS business mailboxes 322, 171 homes
- Route C011 — USPS business mailboxes 197, 480 homes
- Route C029 — USPS business mailboxes 191, 137 homes
- Route C004 — USPS business mailboxes 187, 224 homes
- Route C015 — USPS business mailboxes 152, 618 homes
Select these 5 routes on the route map
Every carrier route in 91789
| Route | Type | Homes | Businesses | Est. median income | Est. owners | Est. families with kids | Est. moved in past year |
|---|---|---|---|---|---|---|---|
| C001 | City | 445 | 29 | $117,185 | — | — | — |
| C002 | City | 269 | 14 | $102,211 | — | — | — |
| C003 | City | 476 | 30 | $107,074 | — | — | — |
| C004 | City | 224 | 187 | $117,185 | — | — | — |
| C006 | City | 340 | 1 | $126,383 | — | — | — |
| C007 | City | 510 | 4 | $102,211 | — | — | — |
| C008 | City | 204 | 103 | $102,211 | — | — | — |
| C009 | City | 482 | 6 | $126,383 | — | — | — |
| C010 | City | 521 | 0 | $110,156 | — | — | — |
| C011 | City | 480 | 197 | $105,346 | — | — | — |
| C013 | City | 509 | 56 | $137,661 | — | — | — |
| C014 | City | 347 | 1 | $110,156 | — | — | — |
| C015 | City | 618 | 152 | $115,454 | — | — | — |
| C017 | City | 575 | 28 | $104,934 | — | — | — |
| C018 | City | 416 | 73 | $106,577 | — | — | — |
| C019 | City | 450 | 0 | $168,616 | — | — | — |
| C020 | City | 520 | 0 | $110,156 | — | — | — |
| C021 | City | 525 | 0 | $176,834 | — | — | — |
| C022 | City | 384 | 103 | $102,211 | — | — | — |
| C023 | City | 522 | 35 | $200,001+ | — | — | — |
| C024 | City | 522 | 4 | $117,008 | — | — | — |
| C025 | City | 171 | 322 | $104,934 | — | — | — |
| C026 | City | 530 | 1 | $165,232 | — | — | — |
| C027 | City | 548 | 3 | $137,464 | — | — | — |
| C028 | City | 328 | 0 | $157,001 | — | — | — |
| C029 | City | 137 | 191 | $106,577 | — | — | — |
| C030 | City | 503 | 109 | $137,661 | — | — | — |
| C031 | City | 411 | 0 | $102,211 | — | — | — |
| C032 | City | 244 | 141 | $69,970 | — | — | — |
| C033 | City | 628 | 1 | $122,991 | — | — | — |
| C034 | City | 677 | 0 | $130,059 | — | — | — |
Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 91789 on the EDDM route map.
How route demographics are estimated
Mailbox counts come from USPS; demographics are estimates
The number of homes and businesses on each carrier route is the current USPS EDDM count. The Census Bureau does not publish figures for carrier routes, so income, homeownership, ages, families, movers and housing age on a route are EDDM2GO estimates built from Census block groups (neighborhood areas of roughly 600 to 3,000 people).
How a route gets its figures: the block-group length-share method
We trace each route's streets every 25 meters and record which block group each stretch falls in. The route's homes are spread along its streets in proportion to length, so a route with 60% of its street length in one block group is assumed to have 60% of its homes there. Each block group then contributes its Census counts in proportion to the share of its housing units that sit on the route (capped at the whole block group). Medians are recalculated from the combined income, home-value and age brackets, the way the Census Bureau computes them, not averaged.
Margins of error
Census survey figures carry a margin of error at 90% confidence; we carry it through the calculation and show it as ±. Our margins treat the route-to-block-group split as exact, so the real uncertainty is larger. Routes with fewer than 100 estimated households, large margins, or streets we could not place are flagged.
Different years
USPS mailbox counts are current. Census figures are 5-year averages for 2020–2024, so a new subdivision may have more homes on the route today than the Census counted. Use the route figures to compare routes with each other, not as an exact head count.
Why some routes show identical figures
Two routes that run through the same block group get the same percentages and medians, because the Census publishes one set of figures for the whole block group. Their mailbox counts still differ, and those are exact.
Route and mailbox counts: USPS EDDM route data. Route demographics: EDDM2GO estimates from U.S. Census Bureau American Community Survey 5-year block-group data (2020–2024) and 2024 cartographic block-group boundaries. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.
Nearby ZIP codes
- 91792 — West Covina city, CA (2.7 mi)
- 91765 — Diamond Bar city, CA (3.4 mi)
- 91791 — West Covina city, CA (3.7 mi)
- 91748 — Rowland Heights CDP, CA (3.9 mi)
- 91724 — Covina city, CA (4.2 mi)
- 91744 — La Puente city, CA (4.8 mi)
- 91768 — Pomona city, CA (4.9 mi)
- 91723 — Covina city, CA (5 mi)
Areas that include 91789
- Diamond Bar, CA ZIP codes — 2 ZIP codes
- Rowland Heights, CA ZIP codes — 2 ZIP codes
- Walnut, CA ZIP codes — 1 ZIP code
- Industry, CA ZIP codes — 5 ZIP codes
- Los Angeles County ZIP codes — 298 ZIP codes
- California ZIP code data
Where it ranks
- No. 14 of 278: highest share of owner-occupied homes in Los Angeles County
- No. 22 of 281: highest median age in Los Angeles County
Mail every home in 91789
Route counts on this page price as Full Service 6.5 × 9 postcards: we print, bundle by carrier route and hand the mailing to USPS. Prefer to take it to the Post Office yourself? Print only costs less and you pay postage at drop-off.
EDDM guides
ZIP code statistics describe the Census ZIP Code Tabulation Area (ZCTA) 91789, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.
Frequently asked questions
- What city is 91789 in?
- 91789 is a Walnut, CA mailing address. By land area, 56% lies inside Walnut, 18% lies inside Industry, 12% lies inside Diamond Bar and 11% lies inside Rowland Heights.
- What county is 91789 in?
- 91789 is in Los Angeles County.
- What is the population of 91789?
- About 40,298 people (±1,155), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 41,235.
- What is the median household income in 91789?
- $125,720 (±$6,903), compared with $99,122 for California as a whole. Half the households in the ZIP code earn more and half earn less.
- How many carrier routes and mailboxes are in 91789?
- 31 USPS carrier routes with 13,516 residential and 1,791 business mailboxes (15,309 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
- What ZIP codes are near 91789?
- The closest, measured center to center: 91792 (2.7 mi, West Covina), 91765 (3.4 mi, Diamond Bar), 91791 (3.7 mi, West Covina), 91748 (3.9 mi, Rowland Heights), 91724 (4.2 mi, Covina) and 91744 (4.8 mi, La Puente).
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.