906
Area code

MI

United States geographic area code, in service since 1961-03-19.

Statusin service
Introduced1961-03-19
JurisdictionMI, US
Local dialing10D
Time zoneEastern / Central
Last verified2026-09-17
Utilization 47.2% of assignable prefixes assigned As of 09/17/2026
0%374 of ~792 assignable NXX values (200–999 excl. N11)100%

Prefix-level assignment does not equal number-level exhaustion; thousands-block pooling extends capacity. First assignment on record 2001-04-19, most recent 2026-09-11.

Area codes serve rate-center geographies, not municipal boundaries. “MI” identifies the jurisdiction, not an exact city footprint.

Top assignees

Ranked by assigned prefixes · initial assignee ≠ current carrier
Largest initial assignees in area code 906
RankAssigneePrefixesShare
01 MICHIGAN BELL TEL CO 67 17.9%
02 PENINSULA FIBER NETWORK, LLC - MI 42 11.2%
03 NEW CINGULAR WIRELESS PCS, LLC - IL 32 8.6%
04 RANGE TELECOMMUNICATIONS 30 8%
05 TELNET WORLDWIDE, INC. 28 7.5%
06 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MI 28 7.5%
07 ONVOY, LLCV - MI 20 5.3%
08 UPPER PENINSULA TEL. CO. 15 4%
09 LEVEL 3 COMMUNICATIONS, LLC - MI 12 3.2%
10 HIAWATHA TEL. CO. 11 2.9%

Important: these are initial assignees from NANPA CO-code records — the carrier a prefix was originally assigned to. Because of number portability, the current serving carrier of any individual number may differ.

Change history

Recorded events for this NPA
  • 1961-03-19Area code 906 entered service.

Planning letters & orders

Primary documents
NANPA planning letters for area code 906
DateDocumentSubject
2021-01-08 PL-556 ↗ Transition to 10-digit dialing (for 988 as 3-digit access to National Suicide Prevention Lifeline) – supersedes PL-544
2020-08-17 PL-544 ↗ Transition to 10-digit dialing (for 988 as 3-digit access to National Suicide Prevention Hotline

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