Sergeant Major Mercedes was born in the Dominican Republic and later moved to Bronx, New York. He enlisted in the Marine Corps in October 2001, and attended Recruit Training at Parris Island, SC, on 8 April 2002. In July 2002, Private First Class Mercedes attended Marine Combat Training at Camp Geiger, NC, in August 2002, where he was the Honor Graduate. He attended the Traffic Management Specialist Course aboard Fort Eustis, VA. In September 2002, he graduated MOS school as the Honor Graduate, was meritoriously promoted to Lance Corporal, and received orders to Marine Corps Base, Headquarters and Service Battalion, III Marine Expeditionary Force, Okinawa, Japan.
In December 2003, Lance Corporal Mercedes was meritoriously promoted to Corporal and assigned as the Non-Commissioned Officer in charge of the Traffic Management Office aboard Camp Courtney, Okinawa, Japan. In January 2004, he received orders to Combat Logistics Company 21, 2nd Marine Logistics Group, at Marine Corps Air Station Cherry Point, NC. During this time, he worked outside of his MOS as an Embarkation Specialist at the Aerial Port of Embarkation, directly supporting missions that included Haiti Hurricane Relief and Operation Iraqi Freedom.
In August 2004, Corporal Mercedes was meritoriously promoted to Sergeant. In May 2005, he attended the Basic Parachutist, Airborne Course aboard Fort Benning, Georgia. He was promoted to Staff Sergeant in March 2008.
In April 2008, Staff Sergeant Mercedes was attached to Combat Logistics Regiment 2, Combat Logistics Battalion 2, for a deployment to Al Anbar Province, Iraq, where he served as the Platoon Commander for Security Operations Company. In November 2009, he received orders to Okinawa, Japan, where he served as the Range Officer-in-Charge, responsible for the annual pistol and rifle marksmanship qualification for all personnel aboard the island. In April 2011, he completed the Martial Arts Instructor Trainer Course in Quantico, VA.
Staff Sergeant Mercedes reported to Drill Instructor School on July 5, 2012. He reported to 1st Battalion, Charlie Company, Recruit Training Regimen. He picked up his inaugural Platoon, 1102, which graduated as the Honor Platoon. Throughout his time in the Drill Field, he held the billets of Drill Instructor, Senior Drill Instructor, Chief Drill instructor and Company First Sergeant. In September 2013, he was promoted to Gunnery Sergeant.
In August 2015, Gunnery Sergeant Mercedes attended the Advanced Course aboard Camp Lejeune, NC where he graduated as the Gung-Ho recipient. In 2016, he deployed with the 11th Marine Expeditionary Unit (MEU) as the Distribution Liaison Cell Officer-in- Charge, supporting distribution operations for the MEU in the 7th and 5th Fleets. Upon completion of the MEU he was frocked to First Sergeant and assigned to the 3rd Amphibious Assault Battalion, Camp Pendleton, CA.
In September 2017, he reported to 1st Battalion, 11th Marines, 1st Marine Division, as the First Sergeant for Battery A. The Battery was deployed under 3rd Battalion, 5th Marine Regiment, to support a WESTPAC in the spring of 2019.
In March 2020, First Sergeant Mercedes was assigned to Marine Air Control Group 28, where he served as the Headquarters and Service Company First Sergeant for Marine Wing Communications Squadron 28. He was selected for promotion to Sergeant Major in November 2021. He reported to 2nd Landing Support Battalion in January 2022, where he assisted in the Battalion's redesignation as the 2d Distribution Support Battalion in support of Force Design 2030. In October 2023, he was assigned to 8th Engineer Support Battalion.
In October 2024, he was assigned as the 31st Marine Expeditionary Unit's Command Senior Enlisted Leader.
Sergeant Major Mercedes holds an Associate's Degree in General Studies. His personal awards include the Meritorious Service Medal with gold star in lieu of second award, Navy and Marine Corps Commendation Medal with gold stars in lieu of third award, and the Navy and Marine Corps Achievement Medal with gold stars in lieu of fifth award.