01821 ZIP Code — Billerica, MA
Middlesex County, Massachusetts
ZIP code 01821 is located in Billerica, Massachusetts, within Middlesex County. It covers approximately 16.59 square miles and serves a population of 30,854 residents. This is a standard ZIP code in the Eastern (ET) timezone, served by area code 978/508.
About ZIP code 01821
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 $532,600. Owner-occupancy is high at 80%, well above the national average.
Median household income is $138,397. The poverty rate of 4% is below the national average.
The dominant occupation class is management, business, and professional, with education and healthcare as the leading industry. The average commute of 28 minutes is near the national average.
Educational attainment is near the national average, with 43% of residents holding a bachelor's degree or higher.
30,854
population
16.59
sq mi land
Standard
ZIP type
Eastern (ET)
timezone
01821 ZIP code map
Cities in ZIP code 01821
Below are the cities the US Postal Service accepts for ZIP code 01821. Using any city not on this list may result in mail delivery delays.
| City | Status |
|---|---|
| Billerica | Preferred |
Nearby ZIP codes
01862 North Billerica (2.3 mi)
01730 Bedford (3.5 mi)
01803 Burlington (4 mi)
01887 Wilmington (4.3 mi)
01805 Burlington (4.3 mi)
01876 Tewksbury (4.5 mi)
01741 Carlisle (5.1 mi)
01824 Chelmsford (5.6 mi)
01852 Lowell (5.9 mi)
01731 Hanscom Afb (6.1 mi)
01801 Woburn (6.4 mi)
01851 Lowell (6.7 mi)
Demographics
updated 05/2026
| Population | |
|---|---|
| Total population | 30,854 |
| Population density | 1,860 / sq mi |
| State FIPS | 25 |
| County FIPS | 017 |
| Geography | |
|---|---|
| Land area | 16.59 sq mi |
| Water area | 0.40 sq mi |
| Latitude | 42.5491 |
| Longitude | -71.2559 |
| Timezone | Eastern (ET) |
| Area code | 978/508 |
Total population by age
Gender
Race & ethnicity
Economics
updated 05/2026
Household income
| Income range | This ZIP | County avg | State avg |
|---|---|---|---|
| Under $50k | 18.9% | 23.8% | 31.3% |
| $50k – $100k | 23.7% | 23.1% | 25.9% |
| $100k – $200k | 45.0% | 32.1% | 28.5% |
| Over $200k | 12.4% | 20.9% | 14.3% |
Demographics & statistics
30,854
Population
1,860
People per sq mi
43.1
Median age
$138,397
Median household income
$56,493
Per capita income
$532,600
Median home value
$2,104
Median monthly rent
80.3%
Home ownership
3.5%
Poverty rate
3.1%
Unemployment
9,457
Housing units
43.2%
Bachelor's or higher
Age distribution
Male
Female
741
Under 5
786
693
5–9
735
828
10–14
879
890
15–19
944
887
20–24
941
2,053
25–34
2,180
1,862
35–44
1,976
2,235
45–54
2,373
1,195
55–59
1,268
1,169
60–64
1,242
1,492
65–74
1,583
726
75–84
770
197
85+
209
← Male
Female →
Age summary
| Group | Count | % |
|---|---|---|
| Under 18 | 5,915 | 19.2% |
| 18 and over | 24,939 | 80.8% |
| 65 and over | 4,977 | 16.1% |
| Median age | 43.1 years | |
Race & ethnicity
White
78.3%
Asian
8.7%
Black or African American
4.8%
Hispanic or Latino
3.4%
Two or more races
3.4%
Other race
1.3%
Native Hawaiian / Pacific Islander
0.1%
| Group | Count | % |
|---|---|---|
| White | 25,029 | 78.3% |
| Asian | 2,770 | 8.7% |
| Black or African American | 1,531 | 4.8% |
| Hispanic or Latino | 1,093 | 3.4% |
| Two or more races | 1,080 | 3.4% |
| Other race | 403 | 1.3% |
| Native Hawaiian / Pacific Islander | 41 | 0.1% |
Household income
| Income range | This ZIP | County avg | State avg |
|---|---|---|---|
| Under $50k | 18.9% | 23.8% | 31.3% |
| $50k – $100k | 23.7% | 23.1% | 25.9% |
| $100k – $200k | 45.0% | 32.1% | 28.5% |
| Over $200k | 12.4% | 20.9% | 14.3% |
Under $10k
1.8%
$10k–$15k
1.3%
$15k–$25k
4.0%
$25k–$35k
2.0%
$35k–$50k
4.7%
$50k–$75k
9.7%
$75k–$100k
11.8%
$100k–$150k
21.1%
$150k–$200k
21.5%
$200k+
22.1%
| Range | % of households |
|---|---|
| Under $10k | 1.8% |
| $10k–$15k | 1.3% |
| $15k–$25k | 4.0% |
| $25k–$35k | 2.0% |
| $35k–$50k | 4.7% |
| $50k–$75k | 9.7% |
| $75k–$100k | 11.8% |
| $100k–$150k | 21.1% |
| $150k–$200k | 21.5% |
| $200k+ | 22.1% |
| Median income | $138,397 |
Housing
Home values
Under $50k
2.9%
$50k–$100k
0.5%
$100k–$150k
1.2%
$150k–$200k
0.5%
$200k–$300k
3.0%
$300k–$500k
36.1%
$500k–$1M
55.1%
$1M+
0.9%
Housing overview
| Metric | Value |
|---|---|
| Median home value | $532,600 |
| Median rent / month | $2,104 |
| Owner occupied | 80.3% |
| Renter occupied | 19.7% |
| Vacant | 2.0% |
| Single-family detached | 74.1% |
| Large apartment buildings | 12.0% |
| Mobile homes | 0.3% |
| Median rooms | 6.4 |
| Avg household size (owned) | 2.83 |
Year built
| Era | % |
|---|---|
| 2020 or later | 0.4% |
| 2010–2019 | 4.7% |
| 2000–2009 | 10.7% |
| 1990–1999 | 10.3% |
| 1980–1989 | 8.5% |
| 1970–1979 | 18.8% |
| 1960–1969 | 23.9% |
| 1950–1959 | 9.7% |
| 1940–1949 | 1.5% |
| 1939 or earlier | 11.5% |
Bedrooms
| Size | % of units |
|---|---|
| No bedroom (studio) | 0.8% |
| 1 bedroom | 8.1% |
| 2 bedrooms | 22.0% |
| 3 bedrooms | 43.5% |
| 4 bedrooms | 19.5% |
| 5+ bedrooms | 5.9% |
Vehicles per household
| Vehicles | % of households |
|---|---|
| No vehicle | 3.7% |
| 1 vehicle | 24.0% |
| 2 vehicles | 45.5% |
| 3 or more | 26.9% |
Heating fuel
| Fuel type | % |
|---|---|
| Utility gas | 70.2% |
| Electricity | 7.6% |
| Propane / LP gas | 4.5% |
| Fuel oil | 16.7% |
| Wood | 0.4% |
| Solar | 0.4% |
| No fuel used | 0.1% |
Households & families
| Household type | Count | % |
|---|---|---|
| Married-couple family | 7,103 | 61.8% |
| Cohabiting couple | 766 | 6.7% |
| Male householder, no spouse | 1,489 | 13.0% |
| Female householder, no spouse | 2,131 | 18.5% |
| Households with children under 18 | 3,561 | 31.0% |
| Households with seniors (65+) | 3,741 | 32.6% |
| Average household size | 2.68 | |
Marital status
| Status | Male | Female |
|---|---|---|
| Never married | 31.3% | 28.5% |
| Married | 58.8% | 54.5% |
| Separated | 1.6% | 1.1% |
| Widowed | 2.6% | 7.6% |
| Divorced | 5.7% | 8.3% |
Education
Less than 9th grade
1.9%
Some HS, no diploma
2.6%
HS graduate
24.7%
Some college, no degree
17.1%
Associate's degree
10.6%
Bachelor's degree
25.5%
Graduate / professional
17.7%
| Metric | % |
|---|---|
| HS diploma or higher | 95.5% |
| Bachelor's or higher | 43.2% |
School enrollment (ages 3–17)
| Type | Count | % |
|---|---|---|
| Nursery / preschool | 574 | 8.2% |
| Kindergarten | 274 | 3.9% |
| Elementary school | 2,503 | 35.8% |
| High school | 1,606 | 22.9% |
| College / grad school | 2,044 | 29.2% |
Employment
Industry of employment
Education & healthcare
22.3%
Professional & management
19.6%
Manufacturing
13.3%
Retail trade
11.2%
Construction
6.8%
Finance & real estate
5.9%
Arts, food & hospitality
5.1%
Public administration
4.6%
Transportation & utilities
3.7%
Other services
3.4%
Information
2.4%
Wholesale trade
1.6%
Agriculture & mining
0.1%
Occupation
| Category | % |
|---|---|
| Management, business & arts | 52.1% |
| Service | 10.7% |
| Sales & office | 18.9% |
| Natural resources & construction | 9.3% |
| Production & transportation | 9.0% |
Employment type
| Type | % |
|---|---|
| Private sector | 83.5% |
| Government | 12.8% |
| Self-employed | 3.6% |
| Unpaid family workers | 0.2% |
Commute
| Method | % |
|---|---|
| Drive alone | 74.2% |
| Carpool | 7.5% |
| Public transit | 1.7% |
| Walk | 0.6% |
| Work from home | 15.1% |
| Other means | 0.9% |
| Avg commute (minutes) | 28.0 |
Poverty
All people
3.5%
Under 18 years
2.1%
18 and over
3.9%
Married-couple families
1.1%
Female-led households
10.2%
Income support
| Source | % of households |
|---|---|
| Social Security | 27.8% |
| Retirement income | 26.5% |
| Supplemental Security | 3.0% |
| Cash public assistance | 4.3% |
| Food stamps / SNAP | 5.6% |
Health indicators
| Condition | % |
|---|---|
| Obesity | 22.2% |
| High blood pressure | 26.2% |
| High cholesterol | 29.4% |
| Diabetes | 7.1% |
| Heart disease | 4.7% |
| Stroke | 2.2% |
| Asthma | 10.1% |
| Arthritis | 20.8% |
| Kidney disease | 2.3% |
| Pulmonary disease | 4.7% |
| Cancer | 6.5% |
| Behavior / access | % |
|---|---|
| Smoking | 12.1% |
| Binge drinking | 17.6% |
| No physical activity | 16.5% |
| Less than 7 hrs sleep | 29.3% |
| Depression | 18.8% |
| Fair or poor health | 8.8% |
| Poor mental health | 13.3% |
| Poor physical health | 7.5% |
| No health insurance | 5.7% |
| Visited doctor (checkup) | 75.2% |
| Visited dentist | 74.7% |
| Cholesterol screening | 91.4% |
| Teeth loss | 9.7% |
Veterans & disability
| Veterans | Count | % |
|---|---|---|
| Civilian veterans | 1,509 | 6.1% |
| Disability | % |
|---|---|
| Any disability | 9.9% |
| Under 18 | 2.3% |
| 18–64 years | 7.5% |
| 65 and over | 28.5% |
Health insurance coverage
| Type | % |
|---|---|
| Private insurance | 88.8% |
| Public insurance | 26.5% |
| No insurance | 1.4% |
| Uninsured under 19 | 0.6% |
Language & origin
Language spoken at home (age 5+)
| Language | Count | % |
|---|---|---|
| English only | 29,327 | 95.1% |
| Spanish | 1,603 | 5.5% |
| Other Indo-European | 185 | 0.6% |
| Asian & Pacific Islander | 894 | 3.0% |
| Other languages | 448 | 1.5% |
Place of birth & citizenship
| Origin | Count | % |
|---|---|---|
| Native born (US) | 26,229 | 85.0% |
| Born in same state | 25,936 | 84.1% |
| Born in different state | 22,482 | 72.9% |
| Foreign born | 293 | 0.9% |
| Naturalized citizen | 4,625 | 15.0% |
| Not a US citizen | 2,611 | 56.5% |
Ancestry
| Ancestry | Count | % |
|---|---|---|
| Italian | 8,346 | 27% |
| French | 2,982 | 9.7% |
| German | 1,153 | 3.7% |
| Arab | 1,114 | 3.6% |
| Polish | 229 | 0.7% |
| Ancestry | Count | % |
|---|---|---|
| Norwegian | 148 | 0.5% |
| Irish | 142 | 0.5% |
| English | 87 | 0.3% |
| Dutch | 24 | 0.1% |
Technology access
| Metric | % of households |
|---|---|
| Computer access | 37.2% |
| Internet access | 96.3% |
Source: U.S. Census Bureau, American Community Survey 2025 estimates.
Frequently asked questions about ZIP code 01821
What city is ZIP code 01821 in?
ZIP code 01821 is primarily assigned to Billerica, Massachusetts.
What county is ZIP code 01821 in?
ZIP code 01821 falls within Middlesex County, Massachusetts.
Is ZIP code 01821 mostly owner-occupied?
80% of occupied units in ZIP code 01821 are owner-occupied, well above the national average.
What is the median household income in ZIP code 01821?
The median household income in ZIP code 01821 is $138,397, above the national median of ~$75,000.
What is the typical home value in ZIP code 01821?
The median home value in ZIP code 01821 is $532,600.
What is the population of ZIP code 01821?
ZIP code 01821 has an estimated population of 30,854 residents, with a density of 1,860 people per square mile.
What timezone is ZIP code 01821 in?
ZIP code 01821 observes the EST timezone.