Lectures are supplemented by weekly, 120-minute “sections”—that is, a smaller group of students with similar prior experiences, led by a member of staff called a Teaching Fellow (TF). Sections will meet once a week to build on the concepts from lecture and offer hands-on practice via “labs” with the course’s assignments (“problem sets”). Your section will be one of your sources of community in CS50.

Attendance at sections is expected. If you have a one-off conflict with your assigned section time, you may temporarily attend another section listed below.

If you are a student who is quarantined or isolating, please reach out to for information on attending alternative sections.


The first sections are in Week 2 on Tue, Sep 14, and Wed, Sep 15. No sections on Tue, Oct 19, or Wed, Oct 20. The last sections before the Test and Final Project will be held during Week 9 on Tue, Nov 9, and Wed, Nov 10. No sections on Tue, Nov 30, or Wed, Dec 1. The final sections, in which you’ll share project “lightning talks” and receive your CS50 t-shirt, will be held on Tue, Dec 7, and Wed, Dec 8. These sections will be held in your usual room and at your usual time.