The program is called the Second Chance Program. According to the CTA, it has helped hundreds of people learn skills and find work.
CTA president Dorval Carter said if a deal isn't reached, some employees could lose their jobs.
"Nobody would give me a chance with my background. But CTA did. And I'm greatly appreciative of the chance that they gave me," Briana Thomas, Second Chance graduate, said.
ABC 7 was unable to reach anyone from the Amalgamated Transit Unions for comment. But according to a published report, they want the Second Chance apprentices to be paid more.