John Ira Thurmond III, M.D. Internal Medicine. 1021 Matlock Road, Suite 101. /. Mansfield, Texas 76063. Phone: 817-225-6888. Fax: 817-377-6570 Get Directions. Primary Phone: 817-225-6888 Fax: 817-377-6570. Dr. Thurmond has joined Texas Health Care as an Internal Medicine Physician..