Arlington, Massachusetts
Arlington is a Census-designated place (an unincorporated community) in Middlesex County, Massachusetts, with 46,308 residents in 2020. It is in Massachusetts's 5th congressional district. It spans 2 state house districts. Its state senate district is Fourth Middlesex District.
County
| County | Share of residents |
|---|---|
| Middlesex County | 100% |
Congressional district
| Congressional district | Share of residents |
|---|---|
| Massachusetts's 5th congressional district (MA-05) | 100% |
Elected officials
| Office | Member | Contact | Share of residents |
|---|---|---|---|
| U.S. Representative (MA-05) | Katherine M. Clark (D) | 202-225-2836 | 100% |
| U.S. Senator | Edward J. Markey (D) | 202-224-2742 · contact form | statewide |
| U.S. Senator | Elizabeth Warren (D) | 202-224-4543 · contact form | statewide |
| State Senator (Fourth Middlesex District) | Cindy Friedman (Democratic) | 100% | |
| State Representative (23rd Middlesex District) | Sean Garballey (Democratic) | 72% | |
| State Representative (24th Middlesex District) | Dave Rogers (Democratic) | 28% |
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
- Arlington laws: search for the Arlington, Massachusetts code of ordinances
- Middlesex County laws: search for the Middlesex County, Massachusetts code of ordinances
State legislative districts
| State senate district | Share of residents |
|---|---|
| Fourth Middlesex District | 100% |
| State house district | Share of residents |
|---|---|
| 23rd Middlesex District | 72% |
| 24th Middlesex District | 28% |
ZIP codes
Percentages mark ZIPs only partly in Arlington: the share of that ZIP's residents living in it.
Get this in your AI agent
Your agent can get Arlington's counties and districts with shares, its ZIP codes (level='zcta'), and its boundary as GeoJSON (get_boundaries). Add https://boundarymcp.com/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:
related_geographies(id="us:place:2501640")
Arlington here is the Census Bureau's place boundary as of January 1, 2025 (a Census-designated place, which has no municipal government). Shares are of 2020 Census population. Districts are the maps in force for the November 3, 2026 election.