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US ZIP Code Profile

ZIP Code 02139
Cambridge, Massachusetts

ZIP code 02139 is in Cambridge, located in Middlesex County, Massachusetts, within the Boston-Cambridge-Newton metro area. Its 2020 Census population was 39,525. The estimated median adjusted gross income per tax return is $66,274, and about 15% of filers report $200,000 or more.

2020 Population
39,525
Census ZCTA
County
Middlesex
FIPS 25017
Median income (est.)
$66,274
IRS SOI 2022
Land Area
1.558 mi²
+ 0.135 mi² water

01Location & Geography

Authoritative geographic identifiers from the U.S. Census Bureau, ANSI, and FIPS standards.

Primary CityCambridge, MA
CountyMiddlesex County (FIPS 25017)
StateMassachusetts (FIPS 25)
Metro Area (MSA)Boston-Cambridge-Newton, MA-NH Metro Area (14460)
Census Region / DivisionNortheast Region · New England Division
Coordinates42.362988, -71.103355
Land / Water Area1.558 mi² land · 0.135 mi² water

02Income & Economics

Distribution of the 18,550 individual tax returns filed in 02139 by adjusted gross income bracket (IRS SOI, 2022).

< $25K
18.5%
$25K–$50K
20.7%
$50K–$75K
16.6%
$75K–$100K
11.1%
$100K–$200K
18.5%
$200K+
14.6%
The $200,000+ bracket accounts for 56% of 02139's total adjusted gross income, from 15% of returns — a concentration that drives the gap between the median ($66,274) and the average.
Estimated median = median adjusted gross income per tax return, interpolated from IRS SOI brackets. Differs from U.S. Census household income.

03Income Over Time

Year-over-year change in 02139's IRS income metrics, 2020–2022.

Median income (2021→2022)
$66,274
▲ 4.8%
Filers earning $200K+
14.6%
▲ 0.1 pt
Total filers
18,550
▲ 2.4%
GET /zipc/v2/zipcodes/02139/soi?year=… $59K 2020 $63K 2021 $66K 2022
Median = adjusted gross income per return, interpolated from IRS SOI brackets. Figures are nominal (not inflation-adjusted).

04Population Trend

Decennial U.S. Census population for the 02139 ZCTA.

2000
34,682
 
2010
36,349
▲ +4.8%
2020
39,525
▲ +8.7%

05Nearby ZIP Codes — Live Radius Search

Drag the slider to filter ZIP codes by distance from 02139. Powered by the same radius endpoint developers call from the API.

GET /zipc/v2/radius

ZIP codes within range of 02139

Cambridge and its immediate neighbors, sorted by distance.

3 mi
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Distance from 02139 to any ZIP

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06USPS Postal Details

Delivery and facility attributes from the monthly USPS dataset.

ZIP ClassificationNon-Unique Zip
Facility TypePost Office
Carrier Route SortB
USPS Finance Number241065
City AliasesCambridge, Cambridgeport, Inman Square

07Frequently Asked Questions

What county is ZIP code 02139 in?

ZIP code 02139 is in Middlesex County, Massachusetts (county FIPS code 25017).

What city is ZIP code 02139?

The primary USPS city for 02139 is Cambridge, MA.

What metro area (MSA) is 02139 in?

02139 is part of the Boston-Cambridge-Newton, MA-NH Metro Area (MSA code 14460).

What is the population of ZIP code 02139?

The 2020 Census population of 02139 was 39,525 residents.

What is the median income in ZIP code 02139?

Based on IRS Statistics of Income data, the estimated median adjusted gross income per tax return in 02139 is about $66,274, with around 15% of filers reporting $200,000 or more. Note that adjusted gross income is a tax measure and differs from U.S. Census household income.