CAS is an acronym for Creativity-Activity-Service. The International Baccalaureate Organization firmly believes that students must be more than academicians; they must grow outside the classroom as well as in it. Consequently, all IB Diploma Candidates need to focus upon the seven CAS learner outcomes during the junior and senior years pursuing activities that develop their creativity (e.g., music lessons, ballet, poetry writing), involve activity (e.g., participating in sports, physical volunteer labor), and provide a community service (e.g., tutoring elementary students, building shelters for the homeless). CAS activities contributing to the IB diploma may begin immediately upon the conclusion of the sophomore year.  Students must fulfill all 7 CAS learner outcomes while demonstrating balanced involvement in all 3 CAS strands during their junior and senior years.

East High PIB students also have CAS requirements. Each year, they must demonstrate involvement in all 3 CAS strands and fulfill a minimum of 3 CAS learner objectives. Freshmen may begin CAS activities during the summer, prior to their freshman year, but only one of their CAS objectives can be accomplished over the summer. Details about EHS PIB CAS requirements and opportunities are outlined in the East High PIB CAS Handbook, which is distributed to students at the beginning of the school year. The official Creativity, Activity, Service guide for IB Diploma Candidates is available on the East High, IB website.