417
Area code
MO
United States geographic area code, in service since 1950-01-01.
Statusin service
Introduced1950-01-01
JurisdictionMO, US
Local dialing10D
Time zoneCentral
Last verified2026-09-17
Utilization 91.5% of assignable prefixes assigned
As of 09/17/2026
0%725 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 2026-07-23.
Area codes serve rate-center geographies, not municipal boundaries. “MO” identifies the jurisdiction, not an exact city footprint.
Top assignees
Ranked by assigned prefixes · initial assignee ≠ current carrier| Rank | Assignee | Prefixes | Share |
|---|---|---|---|
| 01 | SOUTHWESTERN BELL | 100 | 13.8% |
| 02 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO | 88 | 12.1% |
| 03 | BRIGHTSPEED OF MISSOURI, LLC | 82 | 11.3% |
| 04 | NEW CINGULAR WIRELESS PCS, LLC - IL | 51 | 7% |
| 05 | ONVOY, LLC - MO | 40 | 5.5% |
| 06 | RYSTEC, INC | 35 | 4.8% |
| 07 | BRIGHTSPEED OF EAST MISSOURI, LLC | 34 | 4.7% |
| 08 | UNITED STATES CELLULAR - MO | 32 | 4.4% |
| 09 | WINDSTREAM MISSOURI, INC. | 30 | 4.1% |
| 10 | AERIAL COMMUNICATIONS, INC. | 29 | 4% |
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- 1950-01-01Area code 417 entered service.
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 |