Massachusetts
9 congressional districts.
Map
- Very compact (0 to 19)
- Compact (20 to 39)
- Middle (40 to 59)
- Irregular (60 to 79)
- Very irregular (80 to 100)
Select a district for details.
The area outlined with dashes on the map, enlarged so its smaller districts can be seen.
Map used in 2026
2021 enacted plan (H. 4256)
- Drawn by
- the state legislature
- Enacted
- 2021-11-22
- Changed since 2024
- No
Source: Massachusetts Legislature (checked 2026-11-04)
Districts
| District | Irregularity | National rank |
|---|---|---|
| MA-01 | Irregularity score 37 Compact | 284th least compact |
| MA-02 | Irregularity score 63 Irregular | 142nd least compact |
| MA-03 | Irregularity score 41 Middle of the pack | 256th least compact |
| MA-04 | Irregularity score 73 Irregular | 98th least compact |
| MA-05 | Irregularity score 80 Very irregular | 62nd least compact |
| MA-06 | Irregularity score 33 Compact | 308th least compact |
| MA-07 | Irregularity score 94 Very irregular | 14th least compact |
| MA-08 | Irregularity score 67 Irregular | 119th least compact |
| MA-09 | Irregularity score 40 Middle of the pack | 262nd least compact |
Scores describe shape, not intent. How scores work
Massachusetts's senators
- Edward J. Markey, DemocratSeat on the November 3, 2026 ballot: results aren't available yet.
- Elizabeth Warren, Democrat
Senators are elected by the whole state, so district lines don't change who they are. Senators serving as of November 6, 2026. Senators elected in November 2026 take office January 3, 2027. Where this comes from
Partisan fairness
How the 2024 presidential vote splits across these districts. Kamala Harris (Democrat) won 63.0% of the two-party vote and carried all 9 districts.
When one party carries every district, the efficiency gap is large however the lines are drawn, since every vote for the other party counts as wasted. Declination needs districts won by both parties, so it can't be measured here.
- Efficiency gap
- 24.1% Favors Democrats
Counts each party's wasted votes: votes for a losing candidate, plus a winner's votes beyond the half needed to win. The gap is the difference between the two parties' wasted votes, as a share of all votes.
- Mean-median difference
- 3.3 points Favors Republicans
The gap between a party's average vote share across the districts and its share in the middle (median) district. When the middle district leans away from a party's average, that party's voters are packed into a few lopsided districts.
- Declination
- Not measurable
Compares how lopsided each party's wins are. A party that wins a few districts by huge margins and loses the rest narrowly is at a disadvantage. Runs from 0 (even) to 1.
Votes are 2024 presidential results by precinct, added up within each district. This state used the same districts in 2024 and 2026. These measures show how a map turns one election's votes into seats. They don't show why the lines were drawn, and they shift from one election to the next. How fairness scores work