99chambers

U.S. House seat · lines in effect since 2022

Massachusetts's 6th District

A district of about 781,000 people, 50% of adults with a bachelor's degree. It votes D+22.8 relative to the nation for president.

Dan Koh (D) · from Jan 3, 2027Next election Nov 7, 2028The 2026 race →
MA-6

Source: 2026 results: civicAPI; boundaries: Census Bureau TIGER/LineUpdated Nov 7, 2026, 3:01 PM ET

Where it sits among all 435 seats

Every U.S. House seat by partisan lean, from most Democratic to most Republican. Lean is the seat's presidential vote on current lines, relative to the nation.

D+22.8108th most
Democratic
Most DemocraticMost Republican218th seat · the majority line7582MA-64319

Labels below the bar mark 8 other seats in Massachusetts.

Source: 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET

Every race on these lines

Results recomputed from precinct returns as if today's boundaries had always existed, so years compare like for like.

20222026
U.S. HouseD+27.7D+26.8

Outlined: the race for this seat itselfBlank: no race that year

Source: 99chambers results archive: precinct results allocated to current lines; 2026: civicAPIUpdated Nov 7, 2026, 3:01 PM ET

Who lives here, compared

Grey bars show the spread of all 435 seats. Small marks are other seats in Massachusetts. The black marker is MA-6.

Adults with a bachelor's degree50% 89th pct · 4th of 9 in MA

Higher than 89% of seats.

White adults without a degree37% 48th pct · 5th of 9 in MA

Lower than 52% of seats.

Hispanic residents12% 45th pct · 4th of 9 in MA

Lower than 55% of seats.

Black residents3% 22nd pct · 8th of 9 in MA

Lower than 78% of seats.

Asian residents5% 62nd pct · 7th of 9 in MA

Higher than 62% of seats.

People per square mile901 67th pct · 6th of 9 in MA

Denser than 67% of seats.

Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current linesUpdated Oct 13, 2026, 5:06 AM ET

Seats most like this one

Nearest seats on demographics, density and lean.

MA-4
50% college gradsD+22.3Held DMA-2
46% college gradsD+26.1Held DPA-4
49% college gradsD+16.8Held DPA-6
49% college gradsD+12.4Held D

Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current lines; 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET

Who has held it

These lines took effect in 2022.

  1. Dan Koh (D)
    2027– · Won 2026 by 26.8
  2. Seth Moulton (D)
    2023–2027 · Won 2022 by 27.7, 2024 unopposed

Source: Past results: 99chambers results archive (MEDSL, Klarner, state election offices)