Massachusetts area codes — detailed data

NANPA NPA database, current as of July 28, 2026.

Working detail for Massachusetts's 9 area codes: history, capacity forecasts and dialing plans, straight from NANPA's NPA database.

Aggregate footprint: the state's 9 geographic codes currently carry 4,720 active NXX prefixes over 464 rate-center anchorings, with 3,570 prefixes in thousands-block pooling. 9 of the codes serve territory inside FCC top-100 metropolitan statistical areas.

Lineage: 339 came out of 781 in 2001; 351 came out of 978 in 2001; 508 came out of 617 in 1988; 774 came out of 508 in 2001; 781 came out of 617 in 1997; 857 came out of 617 in 2001; 978 came out of 508 in 1997. The remaining codes (413, 617) date back to the plan's early assignments.

Dialing plans: 8 codes use plain ten-digit local dialing (10D); 1 still allows seven-digit local calls. Overlay territories always dial ten digits; the 2021 988-hotline transition moved most others to ten digits as well.

The tightest capacity in the state is 508 (complex 508/774), projected to exhaust 4Q 2045.

Status: no Massachusetts code is currently in jeopardy or active relief planning — capacity is adequate near-term per NANPA.

Code-by-code notes

978 — spawned 351; carved from 508; overlaid by 351.

617 — spawned 508, 781, 857; overlaid by 857; exhaust forecast 3Q 2066.

781 — spawned 339; carved from 617; overlaid by 339.

508 — spawned 978, 774; carved from 617; overlaid by 774; exhaust forecast 4Q 2045.

413 — exhaust forecast 3Q 2048.

774 — carved from 508; overlaid by 508; exhaust forecast 4Q 2045.

857 — carved from 617; overlaid by 617; exhaust forecast 3Q 2066.

339 — carved from 781; overlaid by 781.

351 — carved from 978; overlaid by 978.