CGI's core summer internship program runs for about 10 weeks, from June through August, and is open to college students in technical and business-related fields such as computer science, information technology, and business administration. Interns are placed on project teams that work directly with CGI's clients, contributing to the same consulting and technology work performed by full-time staff, including software development, cybersecurity, and business analysis roles.

Throughout the internship, participants are supported by mentors, managers, and internship coordinators who help guide their project work and professional development. Interns are grouped into a broader cohort alongside other interns, which is intended to build a sense of community and provide peer support during the program. Training sessions and check-ins supplement the day-to-day project work, helping interns build both technical skills and consulting-oriented skills such as client communication and problem-solving.

In addition to the standard summer internship, CGI runs a Bridge Program for rising sophomore and junior college students, which is also about 10 weeks long and is designed to give early-college students initial exposure to the IT industry.