After graduating from college, Lumpkin joined the
U.S. Navy. Before becoming a Navy SEAL, Lumpkin did an abbreviated tour on
USS Vancouver, where he qualified as a surface warfare officer. Lumpkin transferred to Naval Amphibious Base Coronado and subsequently completed Basic Underwater Demolition/SEAL (BUD/S) training with class 162 in 1989. Following SEAL Tactical Training (STT) and completion of six month probationary period, he received the 1130 designator as a Naval Special Warfare Officer, entitled to wear the
Special Warfare insignia. He began his SEAL career with SEAL Team FOUR taking part in counter-narcotics operations in Latin America, mainly operated out of Panama. During this time, he held every leadership position from a squad leader, platoon commander to commanding officer, and he was formally recognized by the Armed Forces Preparedness Association for his Outstanding Contributions to National Security. Immediately after the
attacks of September 11, 2001, he was assigned as the officer in charge of all West Coast SEAL Teams' training and readiness. The teams he trained took part in the invasions of both Afghanistan and Iraq while sustaining zero casualties. During
Operation Iraqi Freedom, Lumpkin served as deputy commander of the Joint Special Operations Task Force for the
Arabian Peninsula. He then served as the deputy commander of all special operations in Iraq. In that role, he oversaw the daily operations of more than 2,000 special operators, and activities at six
high-value target interrogation facilities. Lumpkin returned from Iraq for his final military assignment, working as a liaison to the
U.S. Congress on policy and funding issues to support U.S. Special Operations Forces. The U.S. Department of Defense recognizes him as a specialist in both the Western Hemisphere and Special Operations/Low Intensity Conflict. ==Government service==