Source: ACS 5-Year Estimates (2022), tables B01003 / B19013 / B25077 (ZCTA geography)
📍Quick Facts About 01821
01821 is a ZIP code located in Billerica, MA, within Middlesex County. The ZIP Code Tabulation Area (ZCTA) has a population of approximately 30,854 residents and is classified as Suburban under the USDA RUCA commuting-based system (a technical classification, not a lifestyle description). The median household income is $138,397, and the median home value is $444,300. The home price-to-income ratio is 3.2x.
📊 Data sourced from the U.S. Census Bureau American Community Survey (ACS) 5-Year Estimates, 2018–2022 (ZCTA geography). All figures are survey estimates with margins of error.
Population
25,000 - 50,000
~30,854 residents
Median Income
$138,397
Household median
Home Value
$444,300
Median price
Area Type
Suburban
16.6 sq mi
Location
Detailed Information
Demographics
- Population Range:
- 25,000 - 50,000
- Median Income:
- $138,397
- Classification:
- Suburban
Housing Market
- Median Value:
- $444,300
- Price Range:
- $350,000 - $525,000
- Land Area:
- 16.6 sq mi
Data Quality: 100%
ExcellentUS Census Bureau ACS 5-Year Estimates, 2018–2022 • US Census Bureau
How 01821 Compares — Computed Percentiles
Each percentile is computed from our full database of U.S. ZCTAs with reported data (ACS 5-Year Estimates (2022)). A 90th-percentile value is higher than 90% of comparable ZCTAs.
| Metric | 01821 | Within MA | Within U.S. |
|---|---|---|---|
| Population | 30,854 | 90th percentile in MA | 89th percentile nationally |
| Median household income | $138,397 | 83rd percentile in MA | 96th percentile nationally |
| Median home value (ACS) | $444,300 | 58th percentile in MA | 91st percentile nationally |
ACS estimates carry margins of error, which are larger for small-population ZCTAs. See the Census Bureau's ACS documentation for table-level margins of error.
Zillow Home Value Index
Zillow ZHVI market index (monthly) • As of Monthly
Metro Area: Boston-Cambridge-Newton, MA-NH
Typical Home Value in 01821
Price Appreciation
Historical Price Trend
Historical home values show market trends over time. Values are smoothed and seasonally adjusted.
Observed Trend
The Zillow Home Value Index (ZHVI) for this ZIP code changed by +0.70% over the past 12 months. This is a measured historical change in the index, nothing more.
Note: This figure is a historical observation only. It is not a forecast, not a prediction of future values, and not a recommendation to buy, sell, or invest.
Zillow Home Value Index (ZHVI) data provided by Zillow Group. ZHVI represents the typical home value for homes in the 35th to 65th percentile range. Data is updated monthly and reflects market trends as of the latest update.
Quick Compare
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Frequently Asked Questions about 01821
Sourced data about Billerica, MA
ZIP code 01821 is in Billerica, MA, within Middlesex County.
ZIP Intelligence Report for 01821
Downloadable, print-ready analysis built only from sourced public data
What's included
- Census ACS demographics with table citations and vintage dates
- ACS housing values + Zillow ZHVI market trend with as-of dates
- State and national percentile comparisons (when statistically valid)
- Nearby ZIP comparison table with a documented selection method
- Affordability ratio (home value vs. income) with plain-language context
- Full methodology, data sources, and limitations section
Not included (not available at ZIP level in our sources)
- School quality or district ratings
- Crime statistics
- Investment return projections
- Property-specific values or appraisals
We only report what our sources support — anything missing is labeled, never estimated.
Credits never expire and work for any qualifying ZIP code. Educational information from public data — not financial or real-estate advice. Already purchased? Generate and download reports here.
Get data updates by email
Occasional updates on housing and demographic data for areas like 01821 — sourced, dated, and never more than a few emails a month.
Data Sources, Vintages & Limitations
- Population, income & home value: U.S. Census Bureau, American Community Survey (ACS) 5-Year Estimates, 2018–2022 (2022 vintage). Tables: B01003 (Total Population); B19013 (Median Household Income); B25077 (Median Home Value, owner-occupied). Geography: ZIP Code Tabulation Areas (ZCTAs) — ZCTA boundaries approximate postal ZIP boundaries and may not match exactly.
- Area classification ("Suburban"): derived from USDA ERS Rural-Urban Commuting Area (RUCA) codes, 2010 revision (based on 2010 Census and ACS commuting data). RUCA is a commuting-pattern classification only. It does not measure — and should not be read as describing — schools, jobs, industries, traffic, amenities, safety, or lifestyle. It can be counterintuitive for small, island, or special-use ZCTAs.
- Home value trend: Zillow Home Value Index (ZHVI), smoothed, seasonally adjusted — all homes. ZHVI is a market price index and is reported separately from the ACS survey-based median home value above; the two measure different things and are never blended on this site. Latest ZHVI reporting month shown in the trend module. © Zillow. Data provided via Zillow Research; subject to Zillow's terms of use.
- Freshness: ACS data is released annually by the Census Bureau; this profile reflects the vintage above. Record last updated in our database: November 27, 2025.
- What we do not publish: we do not have verified ZIP-level data for schools, crime/safety, commute quality, climate, or amenities, so this profile makes no claims about them. See our methodology.