Below is a representation of ranks and typical pay grades:

• Special Agent (GS 5 - GS 13)

• Supervisory Special Agent (SSA) or Group Supervisor or Resident Agent in Charge (GS-14)

• Assistant Special Agent in Charge (GS-15)

• Deputy Assistant Special Agent in Charge (GS-15)

• Special Agent in Charge or SAIC/SAC (GS-15 OR Senior Executive Service)

Special Agents:  Every field level criminal investigator, regardless of their years of service, is simply known as a "Special Agent." Whether you are a brand new academy graduate or a senior investigator with 20 years on the job, this basic description is attributed to the working men and women that make cases happen. Special Agents are essentially the street level "detectives" of the federal law enforcement community. 

Supervisory Special Agents (SSA) or Group Supervisors (GS): The first line supervisors are typically in the GS-14 range and have some variety in titles based on their locations. In a typical office with several investigative "Groups" or "Squads" (FBI ranks specific), Supervisory Special Agents (SSA) or Group Supervisors (GS) run an investigative unit of 5-10 special agents.  When comparing this position to State and Local police departments, the GS-14 is analogous to a "Sergeant."  HSI and the FBI now routinely use the SSA management title.

However, at a small office where the first-line supervisor is also the highest ranking manager, they (GS-14 Supervisors) are given the title of Resident Agent in Charge (RAC); which also comes with more authority and responsibilities (i.e. analogous to a Lieutenant). An office run by a RAC is typically called the "RAC Office."   

Assistant Special Agent in Charge:  The second-line supervisors are known as Assistant Special Agents in Charge (GS-15) or ASAC; and are responsible for managing several groups (typically 3-5 investigative units).  These ASAC positions are equivalent to Lieutenant and Captain billets within State and Local agencies.  An office where the ASAC is the highest ranking manager in charge, is typically called the "ASAC Office."   

Deputy Assistant Special Agent in Charge:  The third-line supervisor is called a Deputy Assistant Special Agent in Charge (DSAC) and reports directly to the Special Agent in Charge (SAC or SAIC).  DSACs (also typically GS-15) are often responsible for enforcing discipline and executing SAC orders.  The DSAC is essentially the "Deputy Chief," when compared to State and Locals. 

Special Agent in Charge:  The highest ranking criminal investigator in each region is the Special Agent in Charge (SAC or SAIC).  The SAC is the equivalent to the Chief of Police and runs all the sub-offices in his area.  A typical SAC may be in charge of 100-200 personnel within 10+ offices located throughout a wide geographic area (i.e. 20+ counties).   The "SAC Office" is the controlling location for all sub offices in the assigned geographic region.  The SAC reports directly to officials at their respective agencies in Washington DC.

Most large agencies (i.e. DEA, HSI, FBI, ATF, etc.) have some sort of a formal testing, interview and selection process for initial promotions from Special Agent (Field) to Supervisory Special Agent (Management).  The smaller agencies typically only have an interview selection process.FBI Ranks, ASAC DEA, ASAC FBI