IDEX is an acronym for interior design examination. It is the official and only exam required to become a Certified Interior Designer in the state of California.
The exam was written by Castle Worldwide, Inc. (now Scantron) for the California Council for Interior Design Certification (CCIDC).
IDEX®California exam is comprised of 150 multiple-choice questions, it is closed book and you are given 3 hours in which to take the exam.
The exam and certification fee is listed on the CCIDC site:
ďHow to Become a Certified Interior DesignerĒ.