Updated: 8:31 p.m.
The Michigan Republican will announce his campaign in his home state, making him the third House Member to enter the race. Reps. Michele Bachmann (Minn.) and Ron Paul (Texas) have also launched campaigns.
McCotter spokeswoman Michaela Huntley told the Detroit News that the lawmaker had made a decision about whether to run, but she declined to disclose his plans.
McCotter is in his fifth term representing the 11th district but is unknown nationally. He came in last place, with just 2 percent, in the recent Republican Leadership Conference straw poll.
He served two terms as chairman of the House Republican Policy Committee before recommending in July 2010 that the committee be phased out and its funds used to pay down the national debt. The committee was ultimately preserved, with Rep. Tom Price (R-Ga.) installed at its helm.