Michigan area codes — detailed data

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

Full numbering detail for every active Michigan area code: lineage (which code it split from), NANPA exhaust projections, dialing plans and jeopardy status. This is the working data behind the overview page.

Aggregate footprint: the state's 13 geographic codes currently carry 6,847 active NXX prefixes over 657 rate-center anchorings, with 4,679 prefixes in thousands-block pooling. 11 of the codes serve territory inside FCC top-100 metropolitan statistical areas.

Lineage: 231 came out of 616 in 1999; 248 came out of 810 in 1997; 269 came out of 616 in 2002; 313 came out of 313 in 1947; 586 came out of 810 in 2001; 679 came out of 313 in 2025; 734 came out of 313 in 1997; 810 came out of 313 in 1993; 947 came out of 248 in 2002; 989 came out of 517 in 2001. The remaining codes (517, 616, 906) date back to the plan's early assignments.

Dialing plans: 8 codes use plain ten-digit local dialing (10D); 5 still allow 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 989, projected to exhaust 2Q 2038.

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

Code-by-code notes

248 — spawned 947; carved from 810; overlaid by 947; exhaust forecast 4Q 2065.

313 — spawned 313, 810, 734, 679; carved from 313; overlaid by 679; exhaust forecast 2Q 2091.

989 — carved from 517; exhaust forecast 2Q 2038.

734 — carved from 313; overlaid by 679; exhaust forecast 4Q 2044.

517 — spawned 989; exhaust forecast 3Q 2056.

231 — carved from 616; exhaust forecast 1Q 2068.

586 — carved from 810; exhaust forecast 1Q 2082.

616 — spawned 231, 269; exhaust forecast 3Q 2060.

269 — carved from 616; exhaust forecast 3Q 2050.

810 — spawned 248, 586; carved from 313; exhaust forecast 2Q 2056.

Time-zone note: 906 spans two time zones — rare among NANP codes.