Boundary Atlas

ZIP code 01940: Lynnfield, MA

ZIP code 01940 is in Lynnfield (98% of residents) and Peabody (2.5%), in Essex County, Massachusetts. It is in Massachusetts's 6th congressional district. Its state senate districts are Third Essex District (98%) and Second Essex District (2.5%); its state house districts are 20th Middlesex District (98%) and 12th Essex District (2.5%).

13,326residents (2020 Census)
10.1 sq miland area
2cities and towns
1congressional district
5voting precincts

See it on the mapAll of Massachusetts

City and county

City or townShare of ZIP residents
Lynnfield98%
Peabody2.5%

CountyShare of ZIP residents
Essex County100%

Town or county subdivisionShare of ZIP residents
Lynnfield town98%
Peabody city2.5%

Congressional district

Congressional districtShare of ZIP residents
Massachusetts's 6th congressional district (MA-06)100%

State legislative districts

State senate districtShare of ZIP residents
Third Essex District98%
Second Essex District2.5%

State house districtShare of ZIP residents
20th Middlesex District98%
12th Essex District2.5%

Voting precincts

5 voting precincts overlap ZIP 01940. 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://atlas-production-d344.up.railway.app/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:

related_geographies(id="us:zcta:01940")

ZIP 01940 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.