11787 ZIP Code — Smithtown, NY

Suffolk County, New York

ZIP code 11787 is located in Smithtown, New York, within Suffolk County. It covers approximately 14.90 square miles and serves a population of 34,408 residents. This is a standard ZIP code in the Eastern (ET) timezone, served by area code 631.

About ZIP code 11787

The housing stock consists of predominantly single-family detached homes. Most homes were built in the 1960s, giving the area an established character. Median home value is $622,000. Owner-occupancy is high at 87%, well above the national average.

The gap between median ($139,239) and mean household income suggests income inequality — a small number of higher earners pull the average up. The poverty rate of 5% is below the national average. 37% of households receive Social Security income, suggesting a notable retiree or disability population.

The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 32 minutes is near the national average.

Educational attainment is high — 51% of residents hold a bachelor's degree or higher, well above the national average of 33%.

Overall, ZIP code 11787 reflects a community defined by a highly educated population, high homeownership, and a significant Social Security-dependent population.

34,408

population

14.90

sq mi land

Standard

ZIP type

Eastern (ET)

timezone

11787 ZIP code map

Cities in ZIP code 11787

Below are the cities the US Postal Service accepts for ZIP code 11787. Using any city not on this list may result in mail delivery delays.

City	Status
Smithtown	Acceptable
Smithtown	Preferred

Nearby ZIP codes

11780 Saint James (2.6 mi) 11754 Kings Park (2.8 mi) 11788 Hauppauge (2.9 mi) 11767 Nesconset (3.6 mi) 11725 Commack (4 mi) 11749 Islandia (4.2 mi) 11749 Islandia (4.2 mi) 11755 Lake Grove (4.7 mi) 11790 Stony Brook (5.4 mi) 11731 East Northport (5.6 mi) 11722 Central Islip (5.6 mi) 11794 Stony Brook (5.7 mi)

Demographics updated 06/2026

Population
Total population	34,408
Population density	2,309 / sq mi
State FIPS	36
County FIPS	103

Geography
Land area	14.90 sq mi
Water area	0.67 sq mi
Latitude	40.8615
Longitude	-73.2093
Timezone	Eastern (ET)
Area code	631

Total population by age

Gender

Race & ethnicity

Economics updated 06/2026

Household income

Income range	This ZIP	County avg	State avg
Under $50k	18.6%	22.6%	37.0%
$50k – $100k	20.2%	24.7%	27.0%
$100k – $200k	34.5%	34.6%	24.4%
Over $200k	26.6%	18.0%	11.5%

Demographics & statistics

34,408

Population

2,309

People per sq mi

46.9

Median age

$139,239

Median household income

$62,516

Per capita income

$622,000

Median home value

$2,293

Median monthly rent

87.3%

Home ownership

4.8%

Poverty rate

3.6%

Unemployment

10,536

Housing units

51.1%

Bachelor's or higher

Age distribution

Male Female

698

Under 5

712

802

5–9

817

1,030

10–14

1,050

1,366

15–19

1,393

1,179

20–24

1,202

1,471

25–34

1,500

1,580

35–44

1,611

2,763

45–54

2,816

1,563

55–59

1,594

1,285

60–64

1,310

1,548

65–74

1,577

1,048

75–84

1,068

706

85+

719

← Male

Female →

Age summary

Group	Count	%
Under 18	6,945	20.2%
18 and over	27,463	79.8%
65 and over	6,666	19.4%
Median age	46.9 years

Race & ethnicity

White 83.6%

Two or more races 5.3%

Asian 4.9%

Hispanic or Latino 4.2%

Other race 1.1%

Black or African American 0.9%

American Indian / Alaska Native 0.1%

Group	Count	%
White	30,022	83.6%
Two or more races	1,898	5.3%
Asian	1,754	4.9%
Hispanic or Latino	1,521	4.2%
Other race	400	1.1%
Black or African American	312	0.9%
American Indian / Alaska Native	22	0.1%

Household income

Income range	This ZIP	County avg	State avg
Under $50k	18.6%	22.6%	37.0%
$50k – $100k	20.2%	24.7%	27.0%
$100k – $200k	34.5%	34.6%	24.4%
Over $200k	26.6%	18.0%	11.5%

Under $10k 4.0%

$10k–$15k 2.0%

$15k–$25k 2.8%

$25k–$35k 2.6%

$35k–$50k 4.5%

$50k–$75k 7.6%

$75k–$100k 9.8%

$100k–$150k 20.7%

$150k–$200k 14.0%

$200k+ 31.9%

Range	% of households
Under $10k	4.0%
$10k–$15k	2.0%
$15k–$25k	2.8%
$25k–$35k	2.6%
$35k–$50k	4.5%
$50k–$75k	7.6%
$75k–$100k	9.8%
$100k–$150k	20.7%
$150k–$200k	14.0%
$200k+	31.9%
Median income	$139,239

Housing

Home values

Under $50k 0.8%

$50k–$100k 1.2%

$100k–$150k 0.2%

$150k–$200k 0.7%

$200k–$300k 0.8%

$300k–$500k 16.7%

$500k–$1M 75.3%

$1M+ 4.3%

Housing overview

Metric	Value
Median home value	$622,000
Median rent / month	$2,293
Owner occupied	87.3%
Renter occupied	12.7%
Vacant	2.0%
Single-family detached	84.1%
Large apartment buildings	2.6%
Mobile homes	0.7%
Median rooms	7.3
Avg household size (owned)	2.98

Year built

Era	%
2020 or later	0.1%
2010–2019	2.5%
2000–2009	6.9%
1990–1999	6.9%
1980–1989	8.1%
1970–1979	12.7%
1960–1969	37.1%
1950–1959	18.8%
1940–1949	2.6%
1939 or earlier	4.2%

Bedrooms

Size	% of units
No bedroom (studio)	0.6%
1 bedroom	7.6%
2 bedrooms	10.2%
3 bedrooms	38.2%
4 bedrooms	36.7%
5+ bedrooms	6.7%

Vehicles per household

Vehicles	% of households
No vehicle	5.3%
1 vehicle	22.3%
2 vehicles	41.9%
3 or more	30.5%

Heating fuel

Fuel type	%
Utility gas	44.3%
Electricity	4.9%
Propane / LP gas	1.5%
Fuel oil	47.2%
Wood	0.1%
Solar	0.1%
No fuel used	0.7%

Households & families

Household type	Count	%
Married-couple family	7,530	63.8%
Cohabiting couple	574	4.9%
Male householder, no spouse	1,277	10.8%
Female householder, no spouse	2,423	20.5%
Households with children under 18	3,690	31.3%
Households with seniors (65+)	4,218	35.7%
Average household size	2.85

Marital status

Status	Male	Female
Never married	34.2%	27.6%
Married	56.9%	53.7%
Separated	0.6%	1.0%
Widowed	3.5%	9.4%
Divorced	4.9%	8.3%

Education

Less than 9th grade 2.4%

Some HS, no diploma 2.2%

HS graduate 19.9%

Some college, no degree 14.4%

Associate's degree 10.0%

Bachelor's degree 27.9%

Graduate / professional 23.2%

Metric	%
HS diploma or higher	95.3%
Bachelor's or higher	51.1%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	456	5.5%
Kindergarten	291	3.5%
Elementary school	2,947	35.4%
High school	2,342	28.1%
College / grad school	2,300	27.6%

Employment

Industry of employment

Education & healthcare 30.1%

Retail trade 13.5%

Professional & management 13.1%

Finance & real estate 7.9%

Construction 6.4%

Manufacturing 6.2%

Public administration 5.7%

Arts, food & hospitality 5.2%

Other services 3.7%

Transportation & utilities 2.9%

Information 2.7%

Wholesale trade 2.5%

Agriculture & mining 0.1%

Occupation

Category	%
Management, business & arts	52.4%
Service	13.8%
Sales & office	24.4%
Natural resources & construction	4.9%
Production & transportation	4.5%

Employment type

Type	%
Private sector	74.0%
Government	23.0%
Self-employed	2.9%
Unpaid family workers	0.1%

Commute

Method	%
Drive alone	78.1%
Carpool	3.7%
Public transit	4.1%
Walk	0.4%
Work from home	13.3%
Other means	0.4%
Avg commute (minutes)	32.4

Poverty

All people 4.8%

Under 18 years 3.2%

18 and over 5.2%

Married-couple families 1.8%

Female-led households 10.2%

Income support

Source	% of households
Social Security	36.6%
Retirement income	32.2%
Supplemental Security	5.5%
Cash public assistance	2.1%
Food stamps / SNAP	4.5%

Health indicators

Condition	%
Obesity	25.1%
High blood pressure	28.0%
High cholesterol	31.3%
Diabetes	7.5%
Heart disease	5.3%
Stroke	2.3%
Asthma	9.0%
Arthritis	20.2%
Kidney disease	2.5%
Pulmonary disease	4.9%
Cancer	7.5%

Behavior / access	%
Smoking	11.6%
Binge drinking	17.8%
No physical activity	18.4%
Less than 7 hrs sleep	31.6%
Depression	16.2%
Fair or poor health	8.6%
Poor mental health	11.8%
Poor physical health	7.5%
No health insurance	7.6%
Visited doctor (checkup)	79.3%
Visited dentist	74.7%
Cholesterol screening	93.8%
Teeth loss	8.2%

Veterans & disability

Veterans	Count	%
Civilian veterans	1,795	6.5%

Disability	%
Any disability	10.3%
Under 18	2.9%
18–64 years	7.4%
65 and over	28.3%

Health insurance coverage

Type	%
Private insurance	85.2%
Public insurance	27.2%
No insurance	1.8%
Uninsured under 19	0.8%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	32,998	95.9%
Spanish	852	2.6%
Other Indo-European	314	1.0%
Asian & Pacific Islander	438	1.3%
Other languages	88	0.3%

Place of birth & citizenship

Origin	Count	%
Native born (US)	31,612	91.9%
Born in same state	31,320	91.0%
Born in different state	29,247	85.0%
Foreign born	292	0.8%
Naturalized citizen	2,796	8.1%
Not a US citizen	2,168	77.5%

Ancestry

Ancestry	Count	%
Italian	6,330	18.4%
Arab	3,632	10.6%
French	1,617	4.7%
Polish	294	0.9%
Irish	229	0.7%

Ancestry	Count	%
Norwegian	179	0.5%
English	100	0.3%
German	25	0.1%
Dutch	6	0%

Technology access

Metric	% of households
Computer access	34.3%
Internet access	95.7%

Source: U.S. Census Bureau, American Community Survey 2025 estimates.

Frequently asked questions about ZIP code 11787

What city is ZIP code 11787 in?

ZIP code 11787 is primarily assigned to Smithtown, New York.

What county is ZIP code 11787 in?

ZIP code 11787 falls within Suffolk County, New York.

Is ZIP code 11787 mostly owner-occupied?

87% of occupied units in ZIP code 11787 are owner-occupied, well above the national average.

How educated is the population of ZIP code 11787?

51% of residents hold a bachelor's degree or higher — well above the national average of ~33%, reflecting a highly educated population.

Does ZIP code 11787 have a large retiree population?

37% of households in ZIP code 11787 receive Social Security income, suggesting a significant retiree or disability population.

What is the median household income in ZIP code 11787?

The median household income in ZIP code 11787 is $139,239, above the national median of ~$75,000.

What timezone is ZIP code 11787 in?

ZIP code 11787 observes the EST timezone.