Major Kostovny is currently serving as the Inspector-Instructor, Company A, 4th Assault Amphibian Battalion in Little Creek, Virginia. Received his commission while attending The Citadel in Charleston, South Carolina with a Marine Corps Naval Reserve Officer Training Center (NROTC) scholarship. In May 2012, commissioned as a 2nd Lieutenant and graduated with a Bachelor's Degree in Criminal Justice.
In January 2013, reported to The Basic School as a member of Company B, Basic Officer's Course 2-13 and graduated in July 2013. Reported in August 2013 to 2d Assault Amphibian Battalion (2d AABN) in Camp Lejeune, North Carolina and was assigned to Company C for on the job training. In January 2014, reported to Assault Amphibian School (AAS) for Assault Amphibian Officer Course (AAO 1-14) at Camp Pendleton, California.
After graduation, returned to Company C and was assigned as the 3d AAV Platoon Commander and Company Executive Officer. Promoted to 1st Lieutenant in May 2014. After decommissioning Company C at 2d AABN, was assigned to Company A as the 3d AAV Platoon Commander; several months later was assigned as the Company Executive Officer in conjunction with 3d Platoon Commander until conducting deployment with the North Atlantic Treaty Organization (NATO) Baltic Sea Operations in 2015 with Company C, 1st Battalion, 6th Marine Regiment from May to July 2015. Conducted multiple AAV splashes in Sweden and Poland.
In November 2015, conducted change of operational posture (CHOP) with 3d AAV Platoon to Company C, Battalion Landing Team 1/6 (BLT 1/6) in support of the 22d Marine Expeditionary Unit (22d MEU). After beginning pre-deployment training in January 2016, deployed with 22d MEU in June 2016 and returned in December 2016. Conducted multiple AAV splashes in the Ukraine, Djbouti, and Jordan. Promoted to Captain in January 2017. Remained with Company C, BLT 1/6 until February 2017 upon conducting CHOP back to Company A, 2d AABN. He became the Company A Executive Officer until April 2017.
Volunteered to execute orders to the Tactical Training and Exercise Control Group (TTECG) at Marine Corps Air Ground Combat Center (MCAGCC) at 29 Palms, California in April 2017 as the AAV Representative in the Armor and Maneuver Sections. Earning basic maneuver, advanced maneuver, armor, and fire support team (FiST) instructor qualifications as well as Corridor of Range 410A over the course of 17 Service Level Training Exercises (SLTEs).
Selected on the Commandant's Career Level Education Board (CCLEB) in January 2021 and reported to the United States Army Maneuver Captain's Career Course Class (MCCC 21-01) in October 2021 at Fort Benning, Georgia. Graduated on the Commandant's List in April 2021.
Reported to 2d AABN and filled the role of Assistant Operations Officer from April to June 2021. Took command of Company A in June 2021 and conducted change of command in June 2022. Became the 2d AABN Executive Officer in June 2022 until August 2022 upon arrival of new Executive Officer checking in on orders. In August 2022 became the Headquarters and Service Company Commander until change of command in May 2023. Fulfilled the role of 2d AABN Executive Officer again in May 2023 until volunteering to execute orders to I&I duty in July 2023.