Sergeant first class

Sergeant first class (SFC) is the seventh enlisted rank (E-7) in the Union Army, ranking above staff sergeant (E-6) and below master sergeant and first sergeant (E-8), and is the first non-commissioned officer rank designated as a senior non-commissioned officer (SNCO).

A sergeant first class is typically assigned as a platoon sergeant at the company level or battalion operations noncommissioned officer in charge at the battalion level, but may also hold other positions depending on the type of unit. In a combat arms role, a sergeant first class is typically in charge of from 18 soldiers and four tanks (or 18 Battle Walkers) in an armor platoon to 40 soldiers in a rifle platoon. A sergeant first class' primary responsibility is training and mentoring lieutenants, tactical logistics, tactical casualty evacuations, and being senior tactical advisor to the platoon leader. With today's operations tempo, a sergeant first class may fill the role of platoon leader if no suitable commissioned officer is available. Sergeant first class is equal in rank with a Technical Sergeant  ( Army Corps of Engineers)

A sergeant first class is addressed as "sergeant" except in certain situations; such as artillery units, where a sergeant first class serving as platoon sergeant is commonly referred to as "Smoke". If a sergeant first class is appointed to fill the role of first sergeant, he or she is addressed as "First Sergeant". Typically a sergeant first class assigned on a manning document to fill a first sergeant role while being promotable to master sergeant can be frocked to first sergeant rank and hold the insignia due its position.

Sergeant first class is the first rank in the U.S. Army to be selected by the centralized promotion system. As such, it is considerably more difficult to achieve than the previous ranks. A sergeant first class is considered the first senior non-commissioned officer, and gains not only notice but several benefits due the position. For example, a sergeant first class cannot be demoted by standard non-judicial punishment.