Major McDonald was commissioned as Second Lieutenant in the Marine Corps in May 2014 through the Naval Reserve Officer Training Corps (NROTC), having completed his undergraduate education in International Studies at the Virginia Military Institute.
Following The Basic School from July through February 2015, he was assigned the Military Occupational Specialty of Military Police Officer and reported to Military Police Basic Officer Leadership Course (MPBOLC) in Fort Leonard Wood, MO from March through June 2015. Upon graduation from MPBOLC Captain McDonald reported to 3d Law Enforcement Battalion in Okinawa, Japan. During this tour, Captain McDonald served as Platoon Commander, Executive Officer, Battalion Training Officer, and participated in various exercises in the Pacific theater, including Cooperation Afloat Readiness and Training in Brunei in 2015, Korean Marine Exchange Program as well as Freedom Banner/Ssang Yong in South Korea in 2016, Nonlethal Weapons Executive Seminar in Mongolia in 2016, and Khann Quest in Mongolia in 2017.
In April 2018, Major McDonald received orders to Recruiting Station Richmond, 4th Marine Corps District, Eastern Recruiting Region, Marine Corps Recruiting Command. During this tour, he served as Recruiting Station Operations Officer and later Executive Officer from May 2018 through June 2021. Additionally during this tour, Captain McDonald completed his master's degree in International Relations from Liberty University.
Following a successful completion of recruiting duty, Major McDonald was selected for the Commandant's Career level Education Board (CCLEB) and attended School Year 2022 Expeditionary Warfare School from July 2021 through May 2022.
Upon completion of Expeditionary Warfare School, Major McDonald received orders to Detachment Delta Company, 4th Law Enforcement Battalion, Force Headquarters Group as the Inspector-Instructor.
Major McDonald's personal decorations include the Navy and Marine Corps Commendation Medal, the Navy and Marine Corps Achievement Medal, and the Korean Defense Service Medal.