Siebman is managing partner of Siebman, Burg, Phillips & Smith, LLP which has offices in Sherman, Plano, Marshall, Tyler and Lufkin. His practice involves the representation of clients in state and federal courts across virtually all areas of substantive law throughout Northeast Texas. Siebman is the founding President of the Eastern District of Texas Bar Association and a former member of the Board of Directors of the State Bar of Texas. He is a former law clerk to United States District Judge Paul Brown and is Board Certified in Civil Trial Law by the Texas Board of Legal Specialization.  Siebman has appeared as attorney of record in over 300 cases in the United States District Court for the Eastern District of Texas during his career.