Macomb County was originally served by Detroit's area code 313, one of the original 86 area codes in the North American Numbering Plan. In 1993, area code 810 was split from 313; the service area of 810 initially included all of the former 313 outside of Monroe, Wayne, and Washtenaw counties.
In 1997, Oakland County, bordering Macomb County to the west, was split from area code 810 as area code 248. Area code 586 was first proposed as an overlay on top of 810, to be implemented in 2000. Opposition to the overlay proposal was intense, and 586 was instead implemented as a split. The area code was introduced on September 22, 2001, with permissive dialing ending on March 23, 2002.
Area code 586 serves Macomb County, Michigan, including the following communities:
- Armada, Michigan
- Center Line, Michigan
- Chesterfield Township, Michigan
- Clinton Charter Township, Michigan
- Eastpointe, Michigan
- Fraser, Michigan
- Harrison Township, Michigan
- Lenox Township, Michigan
- Macomb Township, Michigan
- Memphis, Michigan (part by 810)
- Mount Clemens, Michigan
- New Baltimore, Michigan
- New Haven, Michigan
- Ray Township, Michigan
- Richmond, Michigan
- Romeo, Michigan
- Roseville, Michigan
- Saint Clair Shores, Michigan
- Shelby Charter Township, Michigan (very small part by 248)
- Sterling Heights, Michigan
- Utica, Michigan
- Warren, Michigan
- Washington Township, Macomb County, Michigan (part by 248)
- "New area codes may ring in confusion". Crain's Detroit Business. 2000-11-20. Retrieved 2019-04-24.
- "AT&T - Help - Future Area Code Changes - IL, IN, MI, OH". www.att.com. Archived from the original on 2019-04-24. Retrieved 2019-04-24.
|West: 248/947||area code 586||East: 810, 519/226|
|Ontario area codes: 226/519/548, 249/705, 289/365/905, 343/613, 416/437/647, 807|