91384 ZIP Code, Castaic, CA

91384 is a ZIP code in Castaic, California in Los Angeles County. It covers 104 square miles of land. The closest ZIP codes are 91354, 91355 and 91381. 26,478 people live here in 7,124 households. With about 256 people per square mile it is lightly settled, and most homes are owner-occupied (84%). Median household income is $131,689, above the California median of $99,122; 40% of households have children under 18.

Quick facts

Key figures

MeasureValue
Residents26,478
Households7,124
Median household income$131,689
Income per person$41,792
Median age35.8
Homeowners84.1%
Median home value$767,300
Median rent$1,745
Bachelor's degree or higher32.3%
Average commute (minutes)31.3
Households with kids under 1840.4%
Moved in the past year12.7%
Below the poverty line5.7%
Broadband internet96.5%
Speak a non-English language at home37.5%

Household income

% of householdsValue
<$10K3.2%
$10–15K1.2%
$15–25K3.5%
$25–35K2.6%
$35–50K4.6%
$50–75K10.0%
$75–100K9.9%
$100–150K22.8%
$150–200K15.5%
$200K+26.7%

Age

% of all residentsValue
<1011.7%
10–1913.9%
20–247.2%
25–3416.0%
35–4414.5%
45–5413.7%
55–6412.6%
65–747.4%
75+3.0%

Tenure

% of housing unitsValue
Owned, with mortgage67.7%
Owned outright14.8%
Rented15.5%
Vacant2.0%

Type of building

% of housing unitsValue
Detached house85.1%
Townhome1.0%
2–4 units0.8%
5–19 units3.9%
20+ units4.5%
Mobile / other4.8%

Businesses in 91384

343 business establishments with 2,170 employees (ZIP Codes Business Patterns 2023).

EDDM carrier routes

91384 has 12 USPS carrier routes with 7,375 residential and 282 business mailboxes. Open the EDDM route map.

Carrier routes in 91384

91384 has 12 USPS carrier routes (12 rural (R)) with 7,375 residential and 282 business mailboxes. Routes range from 487 homes (R070) to 685 homes (R023); the median route has 618 homes. The Census counted 7,124 households in 91384 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per routeRoutes
1–2490
250–4991
500–74911
750–9990
1,000–1,4990
1,500+0

Best routes in 91384 for…

Most businesses

For B2B offers: office supplies, cleaning, IT, catering and commercial services.

  1. Route R008 — USPS business mailboxes 77, 650 homes
  2. Route R024 — USPS business mailboxes 74, 558 homes
  3. Route R010 — USPS business mailboxes 33, 616 homes
  4. Route R018 — USPS business mailboxes 29, 619 homes
  5. Route R005 — USPS business mailboxes 26, 591 homes

Select these 5 routes on the route map

Every carrier route in 91384

RouteTypeHomesBusinessesEst. median incomeEst. ownersEst. families with kidsEst. moved in past year
R003Rural6728$107,251———
R005Rural59126$168,818———
R008Rural65077$134,363———
R010Rural61633$107,251———
R011Rural64519$151,418———
R012Rural5812$147,087———
R014Rural6551$147,087———
R018Rural61929$168,818———
R023Rural6852$151,418———
R024Rural55874$108,738———
R051Rural6165$130,410———
R070Rural4876$185,242———

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 91384 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

Areas that include 91384

Where it ranks

Mail every home in 91384

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) 91384, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 91384 in?
91384 is a Castaic, CA mailing address. By land area, 7% lies inside Castaic, 6% lies inside Hasley Canyon and 2% lies inside Val Verde; the rest is outside any Census-defined city or community.
What county is 91384 in?
91384 is in Los Angeles County.
What is the population of 91384?
About 26,478 people (±1,280), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 28,585.
What is the median household income in 91384?
$131,689 (±$9,625), 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 91384?
12 USPS carrier routes with 7,375 residential and 282 business mailboxes (7,657 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 91384?
The closest, measured center to center: 91354 (7.8 mi, Santa Clarita), 91355 (9.9 mi, Santa Clarita), 91381 (10.7 mi, Stevenson Ranch), 91390 (10.7 mi, Agua Dulce), 91350 (11.3 mi, Santa Clarita) and 91351 (13.4 mi, Santa Clarita).

This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.