928
Area code
Statusin service
Introduced2001-06-23
JurisdictionAZ, US
Local dialing10D
Time zoneMountain
Last verified2026-09-17
Utilization 81.7% of assignable prefixes assigned
As of 09/17/2026
0%647 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 2001-02-22, most recent 2026-08-14.
Area codes serve rate-center geographies, not municipal boundaries. “AZ” identifies the jurisdiction, not an exact city footprint.
Top assignees
Ranked by assigned prefixes · initial assignee ≠ current carrier| Rank | Assignee | Prefixes | Share |
|---|---|---|---|
| 01 | QWEST CORPORATION | 95 | 14.7% |
| 02 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AZ | 91 | 14.1% |
| 03 | ONVOY, LLC - AZ | 66 | 10.2% |
| 04 | NEW CINGULAR WIRELESS PCS, LLC | 43 | 6.6% |
| 05 | T-MOBILE USA, INC. | 40 | 6.2% |
| 06 | TELEPORT COMMUNICATIONS AMERICA, LLC - AZ | 31 | 4.8% |
| 07 | NAVAJO COMM CO INC - AZ DBA FRONTIER NAVAJO COM | 26 | 4% |
| 08 | LEVEL 3 COMMUNICATIONS, LLC - AZ | 26 | 4% |
| 09 | SMITH BAGLEY INC. DBA CELLULAR ONE OF NE ARIZONA | 24 | 3.7% |
| 10 | CITIZENS UTILITIES RURAL DBA FRONTIER UT RURAL | 24 | 3.7% |
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- 2001-06-23Area code 928 entered service (created from 520).
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 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 |
| 2001-03-27 | PL-268 ↗ | 520 NPA Split, Creating 928 NPA (Arizona) |