Maj. William Zimmer successfully completed Officer Candidates Course and was commissioned a second lieutenant in March of 2012. He reported to The Basic School for duty as a student with Delta Company, course 4-12 and was subsequently assigned to the Basic Logistics Officer Course aboard Camp Johnson, Marine Corps Base Lejeune for military occupational specialty training.
Upon completion of BLOC, he reported for duty with 1st Battalion, 7th Marines in June of 2012. He held the billets of maintenance management officer, and motor transport officer and was promoted to the rank of first lieutenant in March of 2014. During his tour of duty with 1/7, he participated in Operation Enduring Freedom and deployed as part of the Ground Combat Element for Special Purpose Marine Air Ground Task Force – Crisis Response – Central Command. In 2016 he completed his tour with 1/7 and was subsequently assigned orders to serve as a Marine security guard inspecting officer.
In June of 2016, 1st. Lt. Zimmer reported to Marine Corps Embassy Security Group and was assigned to Region 5 Headquarters in Frankfurt, Germany to serve as an inspecting officer. 1st. Lt. Zimmer was promoted in October of 2016. Capt. Zimmer would then serve as the region operations officer and the executive officer until 2020. During this tour, he worked alongside 20 Marine Security Guard (MSG) Detachments across Western Europe and Scandinavia in support of the U.S. Department of State. While assigned to Region 5, he completed the distance Expeditionary Warfare School and attended Survival Evasion Resistance and Escape School in Kittery, Maine. In July 2019 Captain Zimmer was selected for and attended Expeditionary Warfare School in Quantico, Virginia.
In June of 2020, Capt. Zimmer reported to Marine Wing Support Squadron 372 for duty and took command of Motor Transport Company. During this tour he attended Weapons and Tactics Instructor Course 1-21 and Advanced Expeditionary Logistics Instructor Course 2-21 where he earned the secondary skill designators of Weapons and Tactics Instructor (7077) and Expeditionary Logistics Instructor (0477).
In August of 2021, Capt. Zimmer was frocked and promoted to the rank of major and subsequently reported to Combat Logistics Battalion 13 for duty where he served as the Battalion Operations Officer. From November to May of 2023, he deployed with the 13th Marine Expeditionary Unit on their western pacific (WESTPAC) 23-1 deployment operating throughout the U.S. Indo-Pacific Command Area of Responsibility. The MEU supported several bilateral and multinational training exercises to include: Cooperation Afloat and Readiness Training (CARAT) Indonesia, CARAT Singapore, CARAT Sri Lanka, CARAT Timor Leste, Cobra Gold, Ssang Yong and Balikatan.
In June of 2023, Maj. Zimmer reported to Recruiting Station Louisville, Ky. where he currently serves as the RS commanding officer.
His personal awards include: the Meritorious Service Medal, the Navy Marine Corps Commendation Medal with gold star, the Navy Marine Corps Achievement Medal with gold star.