Residential delivery area · New York
ZIP Code 11791: Syosset, NY
ZIP code 11791 uses the postal name Syosset, New York and lies entirely in Nassau County (Census 2020 ZIP-county file). About 26,000 people live there (Census Bureau, ACS 2020-2024). Median household income is $202,962 (Census Bureau, ACS 2020-2024). By Census place, its land lies in Syosset (40%), Muttontown (28%), Laurel Hollow (21%) and Oyster Bay Cove (9%), and 2% in smaller places.
- ACS2020-24
- Census2020
- FHFA2025
- ZBP2023
- IRS2022
- Town
- Syosset · its only residential ZIP
- County
- Nassau County
- Census places
- Syosset (40%) census-designated place; Muttontown (28%); Laurel Hollow (21%); Oyster Bay Cove (9%)
- Metro area
- New York-Newark-Jersey City, NY-NJ
- House district
- NY-3 119th Congress
- State
- New York
- Time zone
- Eastern
- Land area
- 12.5 sq mi · 2,039 people per sq mi
- PO Box ZIPs
- 11773 also use the name Syosset
Where is ZIP code 11791?
11791 centers on 40.828°, -73.503° and covers 12.5 square miles of land plus 0.3 of water. It borders 8 ZIP codes: 11797, 11732, 11753, 11771, 11724, 11803, 11545, 11801.
The map draws ZIP code areas only. For the streets inside 11791, open its center on OpenStreetMap.
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries and the 2023 Gazetteer (2020 ZCTAs); ZIP-to-county shares, Census places and House districts (119th Congress) from the Census 2020 relationship files (shares of land); metro area from the OMB delineation (July 2023); town name and time zone from simplemaps US ZIP Codes (CC BY 4.0).
How does 11791 compare with the rest of Nassau County?
| Measure | 11791 | In Nassau County | In NY |
|---|---|---|---|
| People (ACS 2020-2024) | 25,520 | 25th of 70 | 263rd of 1,826 |
| Median household income | $203k | 5th of 58 | 27th of 1,081 |
| Median home value | $938k | 17th of 62 | 85th of 1,172 |
Its median household income is higher than in 99% of U.S. residential ZIP codes, and it is denser than 85% of all U.S. residential ZIP codes. ZIP codes at the ACS caps ($250,000 or more for household income, $2,000,000 or more for home value) share the top rank.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B19013, B25077); ranks by PlainZIP over residential ZIP codes (ZCTAs).
How many people live in 11791?
The 2020 Census counted 25,879 people in 11791; the ACS, which samples households over 2020-2024, estimates 25,520. Between the 2010 and 2020 censuses its population grew 3.2% (its boundary stayed at least 90% the same).
- People, ACS 2020-2024
- 25,520
- 2020 Census count
- 25,879+3.2% since 2010 (25,076)
- Households
- 8,113
- Median age
- 43.2
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01003, B01002, B11001); 2020 Census (DHC P1); 2010 Census (SF1 P1).
Who lives in 11791?
Of the 25,520 people the ACS estimates in 11791, 28.7% are under 18 and 15.4% are 65 or older. The largest group by race and Hispanic origin is White (not Hispanic) (58.3%), then Asian (not Hispanic) (33.1%).
- Under 1828.7%
- 18 to 6455.9%
- 65 and older15.4%
- White, not Hispanic58.3%
- Asian, not Hispanic33.1%
- Hispanic or Latino4.9%
- Other or two or more2.5%
- Black, not Hispanic1.1%
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B01001 age by sex, B03002 Hispanic or Latino origin by race); shares of the estimated population, small ZIP codes carry wide margins.
What do households in 11791 earn?
Median household income is $202,962 (ACS 2020-2024), the 5th highest of the 58 ranked ZIP codes in Nassau County. It is not measurably different from 2015-2019 ($214,324 in 2024 dollars): the change is within the surveys' margins of error.
- Median household income
- $202,962±$22,340
- Income per person
- $88,245
- Below the poverty line
- 4.1%
- Unemployed (of the labor force)
- 4.9%
- Adults 25+ with a bachelor's degree
- 70.4%
- Adjusted gross income per tax return, 2022
- $275,44012,450 returns; wages 54% of AGI (IRS)
Source: U.S. Census Bureau, ACS 2020-2024 and 2015-2019 5-year estimates (B19013, B19301, B17001, B23025, B15003; 2015-2019 dollars converted with the BLS CPI-U, 1.22699); IRS Statistics of Income, ZIP code data, tax year 2022 (adjusted gross income per return, filed under the address on the return).
What are homes worth in 11791?
FHFA's house price index for 11791, built from repeat sales and appraisals of the same homes, rose 74% from 2015 to 2025 and rose 43% from 2020 to 2025, and moved +2.6% in 2025.
- Median home value (owners' estimate)
- $937,700
- Median gross rent
- $3,019
- Homes owned by their occupants
- 93.5%
- Housing units
- 8,322
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B25077, B25064, B25003, B25001); FHFA House Price Index, annual five-digit ZIP, updated 2026-03-31.
What businesses are in 11791?
1,283 business establishments had a location in this ZIP code in 2023, 18 fewer than in 2018; the most are in professional, scientific, and technical services (ZIP Code Business Patterns).
- Professional, scientific, and technical services235
- Health care and social assistance171
- Wholesale trade124
- Retail trade124
- Other services (except public administration)103
- Accommodation and food services87
Source: U.S. Census Bureau, ZIP Code Business Patterns 2023 and 2018 (establishments with paid employees, by the business's ZIP code).
Which ZIP codes are next to 11791?
| ZIP | Town | People | Household income | Distance |
|---|---|---|---|---|
| 11797 | Woodbury | 9,402 | $193k | 1.7 mi |
| 11732 | East Norwich | 3,228 | $149k | 2.2 mi |
| 11753 | Jericho | 12,435 | $176k | 3.3 mi |
| 11771 | Oyster Bay | 10,908 | $158k | 3.4 mi |
| 11724 | Cold Spring Harbor | 3,073 | $250k+ | 3.5 mi |
| 11803 | Plainview | 29,713 | $188k | 3.5 mi |
| 11545 | Glen Head | 12,172 | $183k | 4.5 mi |
| 11801 | Hicksville | 41,585 | $146k | 4.7 mi |
Source: PlainZIP from the Census 2020 ZCTA boundaries (shared edges) and internal points; figures ACS 2020-2024.
Which other ZIP codes use the name Syosset?
1 more ZIP code carries the postal name Syosset, NY without a residential delivery area: PO boxes at the post office, or a single organization with its own ZIP code. The Census Bureau publishes no figures for it.
| ZIP | County |
|---|---|
| 11773 | Nassau County |
Source: GeoNames postal codes (CC BY 4.0), downloaded 2026-10-09; a ZIP code with no Census ZCTA has no residential delivery area.