Updated on 29 September 2026. What’s new: iassc keeps a yellow belt current for three years, then a 30-question recertification exam is needed to renew it
Your manager has asked you to join a Lean Six Sigma project, and the Green Belt running it suggests you get a Yellow Belt first. The ICYB is that exam: the IASSC Certified Lean Six Sigma Yellow Belt, 60 multiple-choice and true/false questions in 120 minutes, a 70% pass mark and a USD $250 fee, with no prerequisites. It tests the Define, Measure and Control topics at foundation level. This guide covers what each topic asks, a worked example, a four-week study plan and how the certificate stays current.

What does ICYB mean, and what does the exam involve?
ICYB is the short name for the IASSC Certified Lean Six Sigma Yellow Belt, the entry-level credential from the International Association for Six Sigma Certification. IASSC describes the holder as someone who knows the foundations of Lean Six Sigma, can lead a limited improvement project, or can act as a team member on a larger project run by a Green Belt or Black Belt, usually in a part-time role.
The person who passes is not expected to design experiments or run regression models. They are expected to recognise waste, describe a process clearly, read basic statistics and graphs, judge whether a measurement can be trusted, and keep an improvement in place once the team has made it. That practical, supportive level shapes every question on the paper.
The figures below are the ones to plan around.