(a) A presiding judge must be at the time of appointment:
(1) a regularly elected or retired district judge;
(2) a serving or retired business court judge;
(3) a former judge with at least 12 years of service as a district judge or business court judge; or
(4) a retired appellate judge with judicial experience on a district court.
(b) If the judge is retired, he must have voluntarily retired from office, must reside within the administrative region, and must have certified his willingness to serve.
Official text of the Texas Government Code as published by the Texas Legislative Council.