Phone numbers in Mason, Michigan
Mason has 11 phone prefixes in area code 517.
Biggest holders: Verizon Wireless, AT&T (local phone), T-Mobile (including Sprint). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 36%
- Local phone company 18%
- Internet / business phone carrier 27%
- Phone company 18%
Every prefix in Mason
Search the first six digits of a number in this list. If it's here, the number started in Mason with the carrier shown. If it isn't, check the Michigan page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 517-244 | AT&T (local phone) | Local phone company | – |
| 517-362 | T-Mobile (including Sprint) | Mobile carrier | 2024 |
| 517-525 | Verizon Wireless | Mobile carrier | – |
| 517-604 | Verizon Wireless | Mobile carrier | 2002 |
| 517-676 | AT&T (local phone) | Local phone company | – |
| 517-722 | MCImetro (Verizon Business) | Internet / business phone carrier | 2017 |
| 517-833 | Level 3 (Lumen) | Internet / business phone carrier | 2004 |
| 517-883 | First Communications | Phone company | 2008 |
| 517-928 | Verizon Wireless | Mobile carrier | 2019 |
| 517-969 | Windstream (PAETEC) | Internet / business phone carrier | 2006 |
| 517-978 | Acd Telecom | Phone company | 2002 |
Most prefixes are pooled: the 10,000 numbers in each are handed out in blocks of 1,000 to different carriers, and people can also take their numbers to another carrier. So the carrier shown is where the prefix started, not a guarantee about any one number. Source: NANPA central office code records, 2026-10-10.