Massachusetts’s 3rd Congressional District is represented by Lori Trahan (D) in the U.S. House of Representatives. The district is one of Massachusetts’s seats in the 435-member House of Representatives. After the 2020 Census, the average congressional district had 761,169 people, according to the U.S. Census Bureau, and these district boundaries were drawn during the redistricting cycle that followed.
Congressional representatives serve two-year terms and face election every even-numbered year. The next election for this seat will take place on November 3, 2026.
Population
777,948
Median Household Income
$97,616
Population and income: U.S. Census Bureau, American Community Survey 5-year estimates for 2019 to 2023, for district lines in effect on January 1, 2023.
Partisan Lean
D+19
2024 presidential margin (Trump vs Harris). Source: The Downballot.
District boundary, 119th Congress. Boundary data: U.S. Census Bureau TIGERweb. Map tiles: OpenStreetMap.
Lori Trahan and Massachusetts's 3rd Congressional District
Lori Trahan, a member of the Democratic Party, represents Massachusetts's 3rd Congressional District and has held the seat since January 3, 2019. The boundary map for the district is above and the ZIP codes it covers are listed further down this page.
Committee assignments: House Committee on Energy and Commerce.
The current term ends January 3, 2027. The seat is on the ballot on Tuesday, November 3, 2026. Washington office phone: 202-225-3411. Official site: trahan.house.gov.
Current Representative
Rep. Lori Trahan (D)
119th Congress • Democrat • Representing this district since January 3, 2019
Lori Trahan currently represents Massachusetts’s 3rd Congressional District as a member of the Democratic Party in the United States House of Representatives. The representative’s district office helps constituents with federal casework, such as Social Security claims and veterans’ benefits.
2026 Election
On the ballot November 3, 2026
- Lori Loureiro Trahan, Democratic Incumbent
- Gary J. Grossi, Republican
- Dennis R. Conlon, Unenrolled
Source: Massachusetts Secretary of the Commonwealth, 2026 state election candidates, checked September 26, 2026. Write-in candidates are not listed.
Key dates for November 3, 2026
| Register by mail | Saturday, October 24 Application must be postmarked by this date. |
|---|---|
| Register online | Saturday, October 24 |
| Register in person | Saturday, October 24 |
| Early in-person voting | October 17 to October 30 |
| Request a mail ballot | Tuesday, October 27 Application must reach your local election office by 5 p.m. on October 27. |
| Return a mail ballot | Postmarked by November 3 and received by 5 p.m. on November 6, or dropped off by 8 p.m. on November 3. |
| Election Day | Tuesday, November 3, 2026 |
Check your registration with the Massachusetts voter lookup. Dates come from the Massachusetts election office and were checked September 26, 2026. States can change deadlines, so confirm with your election office before you act.
Polling places in Massachusetts are open 7 a.m. to 8 p.m., local time. Confirm your registration and polling place on the official federal voter page for Massachusetts: vote.gov.
What is on the ballot nationally on November 3, 2026
Contact Your Representative
Washington Office
2233 Rayburn House Office Building
Washington, DC 20515
Phone: (202) 225-3411
Online
Committee Assignments
About This District
The district covers parts of Middlesex, Worcester, and Essex counties in Massachusetts. Its largest cities are Lowell (about 116,000), Lawrence (about 89,000), Haverhill (about 68,000), and Methuen Town (about 53,000).
Learn more about congressional districts
- What is a congressional district?
- What does a U.S. Representative do?
- What is gerrymandering?
- How congressional redistricting works
Frequently Asked Questions
Who represents Massachusetts's 3rd Congressional District?
Lori Trahan (D) represents Massachusetts's 3rd Congressional District in the U.S. House of Representatives.
What political party is Lori Trahan a member of?
Lori Trahan is a member of the Democratic Party.
How can I contact Lori Trahan?
You can reach Lori Trahan by phone at 202-225-3411 or through their official website at https://trahan.house.gov.
When does Lori Trahan's current term end?
Lori Trahan's current term in the U.S. House of Representatives ends on January 3, 2027.
Where is Massachusetts's 3rd Congressional District?
Massachusetts's 3rd Congressional District is located in the state of Massachusetts and is one of the 435 voting congressional districts in the U.S. House of Representatives.
What district does Lori Trahan represent?
Lori Trahan has represented Massachusetts's 3rd Congressional District since January 3, 2019. The boundary map for the district is on this page.
Where can I see a map of Lori Trahan's district?
The boundary map for Massachusetts's 3rd Congressional District is on this page. It is drawn from U.S. Census Bureau TIGERweb boundary files for the 119th Congress.
What committees is Lori Trahan on?
Lori Trahan sits on House Committee on Energy and Commerce. Committee assignments come from the Clerk of the House MemberData file.
Is Lori Trahan still in Congress?
This site shows Lori Trahan holding Massachusetts's 3rd Congressional District, checked against the Clerk of the House member list. All 435 House seats are on the ballot on November 3, 2026, so the answer can change with that election.
Nearby Districts in Massachusetts
ZIP Codes in Massachusetts's 3rd Congressional District
This congressional district contains 52 ZIP codes. The most common 10 are shown below; expand the full list to see every ZIP in the district.
11 of these ZIP codes also extend into another Massachusetts district, so a ZIP code here does not always identify a single representative. Examples include 01420 (also in the 2nd), 01436 (also in the 2nd), 01440 (also in the 2nd), 01473 (also in the 2nd), 01731 (also in the 5th and 6th), 01773 (also in the 5th), 01775 (also in the 5th), 01821 (also in the 5th and 6th).
- 01420
- 01430
- 01431
- 01432
- 01434
- 01436
- 01440
- 01450
- 01451
- 01460
View all 52 ZIP codes in this district
- 01420
- 01430
- 01431
- 01432
- 01434
- 01436
- 01440
- 01450
- 01451
- 01460
- 01462
- 01463
- 01464
- 01469
- 01473
- 01474
- 01475
- 01503
- 01510
- 01523
- 01561
- 01718
- 01719
- 01720
- 01731
- 01740
- 01741
- 01742
- 01749
- 01752
- 01773
- 01775
- 01821
- 01824
- 01826
- 01827
- 01830
- 01832
- 01835
- 01840
- 01841
- 01843
- 01844
- 01850
- 01851
- 01852
- 01854
- 01862
- 01863
- 01876
- 01879
- 01886
ZIP-to-district boundaries sourced from the U.S. Census Bureau's 2024-07-30 Block Equivalency File for the 119th Congress. ZCTAs (ZIP Code Tabulation Areas) approximate USPS delivery ZIPs.
U.S. Senators for this state: Edward J. Markey (D), Elizabeth Warren (D)
Last updated September 27, 2026.
Data last checked September 26, 2026.
See how this district compares with another using Compare Districts.