Major Justin Adney graduated from San Francisco State University Obtaining a BS in Criminal Justice and on October 16, 2008 he attended MCRD San Diego. From 2009 to 2011 he served with Echo company, 2nd Battalion 23d Marine Regiment, 4th MARDIV as a 0311 Rifleman. During his time with Echo Co, then Lance Corporal Adney traveled to and participated in a joint training exercise with the Estonian Army. On 13 August, 2011, he was commissioned as a Second Lieutenant from OCS and reported immediately to The Basic School. Designated as a 0402 Logistics Officer, Second Lieutenant Adney attended and graduated from Logistics Operations Course in Camp Johnson North Carolina. 

In August of 2012, Second Lieutenant Adney reported to Alpha Company, Beach and Terminal Operations Group in San Jose, California, and was immediately activated with orders to I Marine Expeditionary Force (MEF). During his time with I MEF, he served as the assistant Motor Transport Officer for 3d Amphibious Assault Battalion, 1st Marine Division and was placed on an Individual Augmentee billet in support of Operation ENDURING FREEDOM. From April 2013 to August 2013 Second Lieutenant Adney served as the Regimental Material Readiness Officer for Regimental Combat Team 7, Regimental S-4 where he coordinated, supervised, tracked, transferred, procured, redistributed, and retrograded equipment throughout Regional Command South West. 

In October of 2013, recently promoted First Lieutenant Adney returned to what was now Supply Company, CLB-453, CLR-4, 4th MLG in San Jose. Starting out at Supply Company he was assigned as the company Operations Officer and later as the Company Executive Officer. In May 2015, First Lieutenant Adney participated in a joint exercise African Lion-15 with the Moroccan Army holding the billet of exercise Operations Officer for the detachment designated to support 2nd Battalion, 25th Marines, 4th Marine Division and all camp personnel. Captain Adney was promoted in late 2015 and in early 2016 was reassigned as the CLB-453, Maintenance Company, Detachment 4 Officer In Charge. Captain Adney dropped to the IRR to attend, and successfully completed, Recruit Fire Academy. In 2019 Captain Adney affiliated with Headquarters Company, 23d Marine Regiment, 4th Marine Division as the Motor Transport Officer (MTO) and S-4 Alpha. Following 2 successful years as the MTO and S4 Alpha, newly promoted to Major, Major Adney was assigned as Head Quarters Company Commander. During his tenure as the Company Commander, Major Adney successfully executed ITX 4-22 as the exercise Camp Commandant for of Camp Wilson, Twentynine Palms. As of current, Major Adney is still assigned as the Head Quarters Company Commander.

In his civilian career, Major Adney is a Firefighter/Engineer with Santa Clara County Fire Department. His personal decorations include the Navy and Marine Corps Achievement Medal.