Sergeant Major Melendez began Recruit Training on 2 May 2004 at Marine Corps Recruit Depot, San Diego, California. He was meritoriously promoted to Private First Class and graduated on 30 July 2004. Following graduation from recruit training, Private First-Class Melendez attended Marine Combat Training (MCT) aboard Marine Corps Base Camp Pendleton, California.
Upon completion of MCT, Private First-Class Melendez attended the Motor Transport School at the US Army Training Center, Fort Leonard Wood, Missouri, in September 2004. In October 2004, Private First-Class Melendez reported to 3d Battalion, 7th Marines, Marine Corps Base Twenty-nine Palms, California, where he served as a Line NCO and Fire Team Leader. He was promoted to the rank of Lance Corporal in September 2005 and deployed with 3d Battalion, 7th Marines to Ramadi, Iraq, where he served as section leader for his truck team with Kilo Company. In March 2006, he was promoted to Corporal and deployed in March 2007 to Ramadi, Iraq. In December 2007, he was promoted to the rank of Sergeant, and in February 2008, he reported to the school of Infantry to perform the duties of a Squad Leader and Training NCO. In January 2010, Sergeant Melendez graduated from Sergeant's Course, Marine Corps Base, Camp Pendleton, where he was recognized as a distinguished graduate. In April 2010, Sergeant Melendez reported to Marine Corps Recruit Depot, San Diego, California, to attend Drill Instructor School, class 3-10. Upon completion of Drill Instructor School, Sergeant Melendez reported to Echo Company, Second Recruit Training Battalion, to serve as a Drill Instructor. During his tour, he held the billets of the Drill Instructor and Senior Drill Instructor. On 2 July 2013, he was promoted meritoriously to Staff Sergeant.
In June 2013, Staff Sergeant Melendez reported to Combat Logistic Battalion 1, 1st Marine Logistics Group, in Camp Pendleton, California. During his time with the unit, he was assigned as a Section Leader, Security Element Leader, and Platoon Sergeant. In July 2014, Staff Sergeant Melendez deployed with Combat Logistic Battalion 1 to Afghanistan in support of Operation Enduring Freedom 14.2. While deployed, Staff Sergeant Melendez performed the duties of Security Element Leader, Assistant Convoy Commander, Company Operations Chief, and Battalion Operations Chief. In January 2015, Staff Sergeant Melendez deployed to Australia, where he performed the duties of Motor Transport Operations Chief and Platoon Sergeant to the Combat Logistic Detachment 1 in support of 1st Battalion 4th Marines, Marines Rotational Force-Darwin. In November 2016, Staff Sergeant Melendez returned to CLB-I to assume the duties of the Truck Master. In May of 2016, Staff Sergeant Melendez reported to the III Marine Expeditionary Force (MEF), G-4, Marine Air Ground Task Force (MAGTF), and Movement Control Center (MMCC). During the time spent at the unit, Staff Sergeant Melendez held the billets of MAGTF Movement Control Coordinator and Logistics Representative for the Joint Movement Control Center (JMCC), in direct support of joint bilateral exercises in the Pacific Area of Operations. In October 2017, he was promoted to the rank of Gunnery Sergeant. In June 2019, Gunnery Sergeant Melendez reported to Marine Air Support Squadron 3, Marine Air Control Group 38, 3d Marine Air Wing, Camp Pendleton, California, and served as the Motor Transport Operations Chief and Headquarters and Service Company First Sergeant. In January 2021, he was promoted to First Sergeant. He reported to Marine Special Operations Company (MSOC) Bravo, 1st Marine Raider Battalion, Marine Raider Regiment, United States Marine Corps Forces Special Operations Command, Camp Pendleton, California. First Sergeant Melendez was deployed to the Indo-Pacific Command Area of Responsibility as the First Sergeant for Special Operations Task Force 511.2. Primarily supporting the Philippines Western Mindanao Command area of operations. In June 2022 First Sergeant Melendez reported to the 4th Marine Regiment, 3d Marine Division, III Marine Expeditionary Force (III MEF) Camp Schwab, Okinawa, Japan, where he served as the Unit Senior Enlisted Leader (USEL). In January 2025, he was promoted to Sergeant Major and reported to 12th LAAB, 12th MLR, 3d Marine Division, III Marine Expeditionary Force (III MEF), Camp Hansen Okinawa, Japan, and currently serves as the Command Senior Enlisted leader.
Sergeant Major Melendez's awards include the Purple Heart, Meritorious Service Medal, Navy and Marine Corps Commendation Medal with three gold stars in lieu of the fourth award, Marine Corps Achievement Medal with a combat distinguishing device with four gold stars in lieu of the fifth award, the Outstanding Volunteer Service Medal, and the Combat Action Ribbon.