Boundary Atlas

ZIP code 02138: Cambridge, MA

ZIP code 02138 is in Cambridge, in Middlesex County, Massachusetts. It is in Massachusetts's 5th congressional district (96%) and Massachusetts's 7th congressional district (4.0%). Its state senate districts are Middlesex and Suffolk District (42%), Suffolk and Middlesex District (38%) and Second Middlesex District (20%); its state house districts are 25th Middlesex District (68%), 29th Middlesex District (32%) and 27th Middlesex District (0.4%).

37,982residents (2020 Census)
2.7 sq miland area
2cities and towns
2congressional districts
14voting precincts

See it on the mapAll of Massachusetts

City and county

City or townShare of ZIP residents
Cambridge100%
Somerville0.4%

CountyShare of ZIP residents
Middlesex County100%

Town or county subdivisionShare of ZIP residents
Cambridge city100%
Somerville city0.4%

Congressional districts

Congressional districtShare of ZIP residents
Massachusetts's 5th congressional district (MA-05)96%
Massachusetts's 7th congressional district (MA-07)4.0%

This ZIP is split between districts. A mailing address in it could be in either; the map or locate_point gives the district for an exact address.

Elected officials

OfficeMemberContactShare of residents
U.S. Representative (MA-05)Katherine M. Clark (D)202-225-283696%
U.S. Representative (MA-07)Ayanna Pressley (D)202-225-51114.0%
U.S. SenatorEdward J. Markey (D)202-224-2742 · contact formstatewide
U.S. SenatorElizabeth Warren (D)202-224-4543 · contact formstatewide
State Senator (Middlesex and Suffolk District)Sal DiDomenico (Democratic)42%
State Senator (Suffolk and Middlesex District)Will Brownsberger (Democratic)38%
State Senator (Second Middlesex District)Pat Jehlen (Democratic)20%
State Representative (25th Middlesex District)Marjorie Decker (Democratic)68%
State Representative (29th Middlesex District)Steve Owens (Democratic)32%
State Representative (27th Middlesex District)Erika Uyterhoeven (Democratic)0.4%

Officials serving now (members of Congress until January 3, 2027). Sources: State legislators: Open States (public domain); Members of Congress: the @unitedstates project, congress-legislators (CC0).

Local government

State legislative districts

State senate districtShare of ZIP residents
Middlesex and Suffolk District42%
Suffolk and Middlesex District38%
Second Middlesex District20%

State house districtShare of ZIP residents
25th Middlesex District68%
29th Middlesex District32%
27th Middlesex District0.4%

Voting precincts

14 voting precincts overlap ZIP 02138. Map them, with each precinct's share of the ZIP's residents.

Get this in your AI agent

Your agent can get these cities, counties, districts and precincts with their shares, and their GeoJSON boundaries, from Boundary Atlas. Add https://boundarymcp.com/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:

related_geographies(id="us:zcta:02138")

ZIP 02138 here is the Census Bureau's ZIP Code Tabulation Area, which approximates the USPS ZIP Code; PO-box-only ZIPs have none. Districts are the maps in force for the November 3, 2026 election.