The Michigan Public Service Commission (MPSC) has approved three geographic area code splits, as
well as a new overlay area to accommodate the growth of telephone numbers.
Local calling areas and the cost of Ameritech calls will NOT change as a result of the new area
codes. Calls that were local before the area code split remain local after the area code split.
* An overlay allows two different area codes to serve the same geographic area at the same time.
Unlike an area code split, an overlay allows everyone to keep their existing area code and
telephone numbers. The new overlay area codes may be assigned to customers who request new telephone
lines.
Central Michigan 517/989 Area Code Split:
The southern portion of the 517 area code (Lansing LATA*), will retain the 517 area code,
while the Saginaw LATA, the northern portion of the 517 area code, will become the 989 area code.
Saginaw, Midland, Bay City, Mount Pleasant and Alpena are among the cities that will receive the
989 area code. Check the prefix list to determine if your area code is changing.
*A LATA is a local access transport area. Michigan has five LATAs: the Detroit LATA, the Saginaw
LATA, the Lansing LATA, the Grand Rapids LATA and the Upper Peninsula LATA.
Dialing Procedures for the 517/989 Optional Period: (From 04/17/01-10/06/01)
During this six-month period, Ameritech calls made between
the 517 and 989 area codes may be dialed using 7-digits or may be dialed using 11 digits (1 +
area code + 7-digit telephone number).
Mandatory Dialing Procedures for the 517/989 Areas:
After the optional dialing period concludes on October 6,
2001, the 989 area code must be used for all calls to the new area code. In addition, Ameritech
calls made between the 517 and 989 areas must be dialed using 11 digits.
Eastern Michigan 810/586 Area Code Split
Telephone customers in Macomb County will be assigned the new 586 area code, while the 810 area
code will continue to serve the rest of the area it does today. Telephone customers located along
the border of Macomb County should view the prefix list to determine how their area code is
affected, as area code boundaries do not precisely match county boundaries.
Dialing Procedures for the 810/586 Optional Period: (From 01/26/02-06/08/02)
During this six-month period, calls to Macomb County will complete using either area code.
Ameritech calls made between the 810 and 586 area codes may be dialed using 7-digits, or may
be dialed using 11 digits (1 + area code + 7-digit telephone number).
Mandatory Dialing Procedures for the 810/586 Areas:
The 586 area code must be used for all calls to the new area code. Also at that time, Ameritech
calls made between the 810 and 586 area codes must be dialed using 11 digits.
Eastern Michigan 248/947 Area Code Overlay
The new overlay area code, 947, will serve the same geographic area as the existing 248 area code.
Unlike an area code split, an overlay allows everyone to keep their existing area code and
telephone numbers. Telephone numbers in overlay area codes are assigned to new phone lines. Starting
in July 2002 prefixes in the new 947 overlay area code will be activated on an as-needed basis as
prefixes in the existing 248 area code are exhausted.
Dialing Procedures for the 248/947 Optional Period: (From 09/22/01-March 2002)
Starting January 26, 2002 Ameritech customers in the 248 geographic area may begin dialing 10
digits (area code + 7-digit telephone number) for all local calls.
Mandatory Dialing Procedures for the 248/947 Areas:
Effective June 8, 2002 Ameritech callers in the 248/947 area code will be required to use the
new 10-digit dialing pattern to complete all local calls. Customers placing calls to long
distance points will continue to dial 11-digits (1 + area code + telephone number.) NOTE: The
elimination of 7-digit dialing in June will take approximately one week to complete. Until the
conversion is complete, customers may experience different dialing patterns from different
locations.
Southwestern Michigan 616/269 Area Code Split
A north/south geographic split will be implemented with the northern portion of the 616
area code retaining the 616 area code. The dividing line follows the northern boundaries of
the Saugatuck, Hamilton, Hopkins, Wayland, Middleville, Hastings and Woodland rate centers.
Telephone customers in these rate centers and those to the south of these rate centers will
receive the new 269 area code. A list of the affected telephone number prefixes will be added
to this site when available.
Dialing Procedures for the 616/269 Optional Period: (From 07/13/02-02/15/03)
For the next seven months, callers can complete calls to the affected area by dialing either
the 269 or the old 616 area code. Ameritech calls made between the 616 and 269 area codes may be
dialed using 7-digits or may be dialed using 11 digits (1 + area code + 7-digit telephone number).
Mandatory Dialing Procedures for the 616/269 Areas:
After the optional dialing period concludes on February 15, 2003, Ameritech calls made between
the 616 and 269 areas must be dialed using 11 digits.
