11751 ZIP Code, Islip, NY

11751 is a ZIP code in Islip, New York in Suffolk County. It covers 4.0 square miles of land. The closest ZIP codes are 11730, 11706 and 11718. 13,726 people live here in 5,040 households. At about 3,461 people per square mile it has suburban density, and most homes are owner-occupied (83%). Median household income is $116,559, above the New York median of $85,974; the median age is 45.6, older than most ZIP codes.

Quick facts

Key figures

MeasureValue
Residents13,726
Households5,040
Median household income$116,559
Income per person$51,520
Median age45.6
Homeowners83.4%
Median home value$563,100
Median rent$2,257
Bachelor's degree or higher35.7%
Average commute (minutes)27.5
Households with kids under 1827.1%
Moved in the past year10.4%
Below the poverty line5.5%
Broadband internet85.4%
Speak a non-English language at home10.8%

Household income

% of householdsValue
<$10K4.9%
$10–15K0.2%
$15–25K4.9%
$25–35K3.5%
$35–50K3.4%
$50–75K15.1%
$75–100K11.5%
$100–150K16.2%
$150–200K19.3%
$200K+21.2%

Age

% of all residentsValue
<1010.5%
10–1910.3%
20–245.2%
25–3413.2%
35–4410.0%
45–5413.1%
55–6417.3%
65–7411.9%
75+8.5%

Tenure

% of housing unitsValue
Owned, with mortgage50.6%
Owned outright29.5%
Rented15.0%
Vacant5.0%

Type of building

% of housing unitsValue
Detached house68.9%
Townhome9.3%
2–4 units6.1%
5–19 units6.4%
20+ units7.6%
Mobile / other1.7%

Businesses in 11751

349 business establishments with 3,416 employees (ZIP Codes Business Patterns 2023).

EDDM carrier routes

11751 has 14 USPS carrier routes with 5,261 residential and 298 business mailboxes. Open the EDDM route map.

Carrier routes in 11751

11751 has 14 USPS carrier routes (14 city (C)) with 5,261 residential and 298 business mailboxes. Routes range from 265 homes (C005) to 500 homes (C009); the median route has 364 homes. The Census counted 5,040 households in 11751 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per routeRoutes
1–2490
250–49913
500–7491
750–9990
1,000–1,4990
1,500+0

Best routes in 11751 for…

Most businesses

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

  1. Route C018 — USPS business mailboxes 97, 291 homes
  2. Route C011 — USPS business mailboxes 67, 295 homes
  3. Route C009 — USPS business mailboxes 39, 500 homes
  4. Route C010 — USPS business mailboxes 31, 435 homes
  5. Route C012 — USPS business mailboxes 29, 351 homes

Select these 5 routes on the route map

Every carrier route in 11751

RouteTypeHomesBusinessesEst. median incomeEst. ownersEst. families with kidsEst. moved in past year
C001City2971$174,919———
C002City4263$140,256———
C003City3662$99,400———
C004City3593$151,226———
C005City2652$174,919———
C006City3723$137,963———
C008City3612$137,963———
C009City50039$104,833———
C010City43531$137,963———
C011City29567$104,833———
C012City35129$102,835———
C013City44718$99,400———
C015City4961$104,833———
C018City29197$102,835———

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 11751 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 11751

Where it ranks

Mail every home in 11751

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) 11751, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 11751 in?
11751 is a Islip, NY mailing address. By land area, 100% lies inside Islip.
What county is 11751 in?
11751 is in Suffolk County.
What is the population of 11751?
About 13,726 people (±953), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 14,790.
What is the median household income in 11751?
$116,559 (±$17,531), compared with $85,974 for New York as a whole. Half the households in the ZIP code earn more and half earn less.
How many carrier routes and mailboxes are in 11751?
14 USPS carrier routes with 5,261 residential and 298 business mailboxes (5,559 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 11751?
The closest, measured center to center: 11730 (1.5 mi, East Islip), 11706 (2 mi, Bay Shore), 11718 (2.7 mi, Brightwaters), 11752 (2.8 mi, North Great River), 11739 (2.9 mi, Great River) and 11722 (3.8 mi, Central Islip).

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