Machines can be reprogrammed to follow the commands of someone other than its original creator, usually Skynet. This ability is used by the Resistance to reprogram Terminators, and by Terminators to reprogram other Terminators.
However, Reprogramming can be unreliable. Sometimes, a reprogrammed Terminator will "go bad"; a reprogrammed Terminator in the Future War inexplicably went rogue and killed many Resistance fighters in a bunker, and Cameron tried to kill John Connor after her chip was damaged.
Known Reprogrammed Terminators
- Main article: :Category:Reprogrammed Terminators
- C890.L, temporarily reprogrammed by Dudley in The Terminator: Secondary Objectives.
- T-800 in Terminator 2: Judgment Day
- Eve and two T-1000 in Terminator 2: The New John Connor Chronicles
- T-850 in Terminator 3: Rise of the Machines
- T-950 in Terminator 3: Fragmented
- Eliza in Terminator Hunt
- Uncle Bob in Terminator: Infinity
- Cameron in Terminator: The Sarah Connor Chronicles
- The Rogue in Terminator: The Sarah Connor Chronicles
- Queeg in Terminator: The Sarah Connor Chronicles episode "Today Is The Day, Part 1" and "Today Is The Day, Part 2"
- An HK-Tank reprogrammed and piloted by John Connor in the video game Terminator Salvation
- Moto-Terminator in the film Terminator Salvation
- Pops in Terminator Genisys
- An HK-Tank for the final assault on Skynet in Terminator: Resistance
- T-850's CPU chip in Terminator: Resistance
- In the Sarah Connor Chronicles timeine, Skynet later added a self-destruct feature to Terminator chips upon chip removal, so that Terminators couldn't be reprogrammed, such as Rosie.
- Some Resistance fighters greatly disliked being surrounded by reprogrammed "metal" all the time. [Episode needed]
- They also sometimes had problems taking orders from reprogrammed metal, such as some of the crew under Captain Queeg on the USS Jimmy Carter.
- Some Resistance fighters didn't like John separating himself from other humans, and only spending time with Cameron. This caused Jesse Flores to go back in time in an attempt to alienate John Connor by framing Cameron for the murder of Riley Dawson.
- Reprogrammed Terminators were sometimes referred to by Resistance fighters as "scrubbed". 
- In Terminator Genisys, Guardian was reprogrammed and sent back in time by an unknown party who purposefully erased all knowledge of their identity from Guardian's mind so that no one else would know who they are and so Skynet couldn't find out who they were and try to stop them.
- Cameron: (referring to a reprogrammed terminator who went rogue) Sometimes they go bad. No one knows why.
- Terminator: The Sarah Connor Chronicles, "Dungeons & Dragons"