U.S. District Judge Sam Cummings announced he will be taking senior status beginning Jan. 1.
He has decided to continue his service on the bench afterward, with a reduced civil and criminal caseload.
At that time, the president can begin the process of selecting a nominee to succeed the judge, which must be confirmed by the senate.
Judge Cummings has presided over the Lubbock, Abilene and San Angelo divisions of the northern district of Texas since his appointment by President Reagan 27 years ago.
He received his bachelor's degree from Texas Tech and graduated cum laude from Baylor Law School.
He will turn 70 in October.