This is a list of telephone area codes in the U.S. state of Michigan:
An additional planned area code that is not yet in service:
Michigan's numbering plan expanded from three area codes in 1947 to twelve:
Thus, as of October 30, 2019, the original area code 313 has been split and overlaid five times, producing six of Michigan's twelve area codes; original area code 616 has been split three times, accounting for four of the twelve area codes; and area code 517 has been split once, accounting for the last two of the twelve area codes.