Sarmiento served in the United States Navy from 1988 to 1997, and the United States Naval Reserve from 2002 to 2006, earning his VFW eligibility by serving in Operations Desert Shield/Storm. In recognition of his service, he received the Navy Achievement Medal, Navy Combat Action Ribbon, Navy Good Conduct Medal, the Southwest Asia Service Medal with three campaign stars, the Saudi Arabian Medal for the Liberation of Kuwait, Kuwait Medal for the Liberation of Kuwait and numerous other medals and ribbons. In 2003, he earned the title of the Naval Reserve Center Sailor of the Year at Fort Dix.

Sarmiento joined the VFW in 1990 at Post 5579 in Gibbstown, New Jersey, where he maintains his Gold Legacy Life membership. He has served in elected and appointed positions at the Post, District and Department levels, culminating with his election as the VFW Department of New Jersey Commander from 2018 to 2019. On the national level, he served as the VFW Inspector General from 2019 to 2020, and served on the National Security and Foreign Affairs Committee, General Resolutions Committee, and as Special Aide-de-Camp. He is a life member of the Military Order of the Cootie, at Ky-Yi Pup Tent #1 in Delaware.