These are the groups mentioned in the series.
- HR - An organization of corrupt cops within the NYPD. They collaborate with many different organized crime syndicates within New York, providing protection and assistance for a profit as well as being active member's of the city's drug market.
- Inner Circle - Carl Elias's organized crime syndicate. Their goal was to eliminate the 5 Italian crime families in New York City and wipe out the Russian mafia.
- Russian Mob - The former dominant organized crime power of Brighton Beach. The Russians were the first targets of the Inner Circle. Scarface killed family patriarch, Ivan Yogorov and his son Peter is now the organization's head.
- CIA - The Central Intelligence Agency has become willing to overstep the legal boundaries of its authority, getting involved in the drug trade and carrying out assassinations of US citizens. Mark Snow is charged with locating Reese after he resurfaces in NYC. Reese worked for the CIA for several years after his military service.
- FBI - The FBI gets involved in several operations in NYC. A task force led by Special Agent Nicholas Donnelly is set up to track down Reese after he reappears in NYC and Cater enters his prints into the national data base. The FBI also takes the lead role in the dismantling of the crooked cop organization [HR].
- ISA - The Intelligence Support Activity is a covert wing of the US Army. Due to the nature of the missions and the covert nature of the organisation, the ISA is very secretive and compartmentalized. The ISA was put in charge of taking direct action against the relevant numbers the Machine produces as well as protecting the source of the information it receives.
- Vigilance - A group of privacy extremists seeking to expose and abolish privacy-invading activities and stop the people behind them.
- Decima Technologies - A private group of intelligence operatives operating under the protection of the Chinese military. They discover the existence of the machine and do all they can in order to determine it's location.
- Northern Lights - A group of high level US government bureaucrats who receive the relevant numbers from the machine and pass the information on to the ISA to liquidate the threats.