Representative Kenny Marchant of Texas announced on Monday that he plans to retire, becoming the fourth Republican House member from Texas in recent weeks to head for the exits rather than face re-election in 2020 in a state that is rapidly becoming more competitive.

“It is time for me to announce that I will not seek another term as Congressman from the 24th District of Texas,” Mr. Marchant said in a statement. “I am looking forward to finishing out my term and then returning to Texas to start a new chapter.”

Mr. Marchant, who was first elected in 2004, won his suburban Dallas district by comfortable margins for over a decade, but last year he prevailed by only three points against a Democratic opponent who had relatively modest financial resources. Mr. Marchant, a low-key member and reliably conservative vote, sits on the influential Ways and Means Committee.

With Mr. Marchant, a total of 11 House Republicans plan to retire or seek another office in 2020; just three House Democrats have announced they won’t run again. The Democrats hold a 37-seat majority in the House with two vacancies at the moment.