In the United States Army, the acronym SSG stands for staff sergeant. A staff sergeant carries an enlisted rank of E-6.
Comparable ranks in other branches of the U.S. military include PO1 for a Petty Officer First Class in the Navy or Coast Guard, a TSgt for a Technical Sergeant in the Air Force and SSgt for a Staff Sergeant in the Marine Corps. These are all E-6 ranks. Enlisted ranks for the U.S. military range from E-1 to E-9, with E-1 being the lowest rank. For example, a Private in the U.S. Army receives a rank of E-1.