Freshman Rep Travis Childers of Booneville, a self-described conservative Democrat, is defending his seat against a challenge by Republican state Sen. Alan Nunnelee of Tupelo.
Although either could face a primary challenger, the two are considered favorites to win their party nominations.
They also could face nontraditional party candidates in the general election. Hernando resident Les Green, a high school math teacher, said he is considering a run as an independent.
The qualifying deadline is March 1. The primary is June 1.
Nunnelee, 51, filed qualification papers Wednesday, the same day the National Republican Congressional Committee granted him “contender” status, meaning he has met or exceeded pre-established fundraising goals.
It also means the party is likely to play a heavy hand in the race, offering fundraising and staffing help.
The Republicans would need to win 40 seats to take back a majority in the House of Representatives. The GOP is honing in on any possible chance to chip away at the majority and is particularly interested in this Deep South seat that the party only recently lost to a Democrat.