ICGB
IASSC Certified Lean Six Sigma Green Belt Exam
More study resources
Cheat sheet
Keep the key ideas within reach.
ExploreKey terms
Get comfortable with the vocabulary.
ExploreStudy plan
Give each week a clear focus.
ExploreCommon mistakes
Understand the traps and how to avoid them.
ExploreCase studies
Put your knowledge to work in context.
ExploreExam-day guide
Prepare for the day ahead.
ExploreAbout this exam
The IASSC Certified Lean Six Sigma Green Belt (ICGB) is a professional credential for practitioners who are well versed in the core to advanced elements of Lean Six Sigma methodology. Green Belts lead improvement projects or serve as team members on more complex projects led by a Certified Black Belt, typically in a part-time role. The credential requires competence in subject matter across the DMAIC phases-Define, Measure, Analyze, Improve, and Control-as defined by the IASSC Lean Six Sigma Green Belt Body of Knowledge. The exam is a 100-question, closed-book, proctored test with a 3-hour allotted time; some forms may include up to 10 additional non-graded questions. It contains approximately 20 multiple-choice and true/false questions from each major section of the Body of Knowledge. There are no prerequisites to sit for the exam, and a minimum score of 70% is required to earn the designation. Preparation is self-directed: IASSC recommends, but does not require, training through a qualified institution, trainer, or corporate program, plus some real-world Lean Six Sigma project experience. A non-proctored Green Belt Evaluation Exam is available to help candidates gauge readiness. Exam vouchers cost $350 USD. Certification is recognized perpetually, with a classification system that recognizes certifications as “Current” for a period of three years under the IASSC Recertification Policy effective March 1, 2017.
What you'll study
About ICGB preparation
What is the format of the IASSC Green Belt exam?
It is a 100-question, closed-book, proctored exam with a 3-hour allotted time. Some forms may include up to 10 additional non-graded questions. Questions are approximately 20 multiple-choice and true/false items from each major section of the IASSC Green Belt Body of Knowledge, covering Define, Measure, Analyze, Improve, and Control.
How difficult is the exam, and what score do I need to pass?
IASSC does not publish a difficulty rating, but the exam demands a thorough understanding of all DMAIC phases at a high level of proficiency. You must achieve a minimum score of 70% to earn the IASSC Certified Green Belt designation. Because questions span the full Body of Knowledge, broad preparation across all five phases is essential.
Are there any prerequisites to sit for the exam?
No. IASSC states there are no prerequisites required to sit for the IASSC Certified Lean Six Sigma Green Belt Exam. However, IASSC recommends-but does not require-that candidates obtain Lean Six Sigma training through a qualified institution, trainer, or corporate program, and have some degree of real-world Lean Six Sigma work and project application experience.
How much does the exam cost, and how do I purchase it?
A Green Belt Exam Voucher costs $350 USD and can be purchased through the link provided on the IASSC Green Belt certification page. The exam is administered at more than 8,000 testing centers in 165 countries, through the PeopleCert Online Proctoring system, and by hundreds of IASSC Accredited Providers. On-demand web-based and IASSC-PearsonVue exam purchase options are also listed.
What happens if I fail-can I retake the exam?
The source text does not state a retake policy, including any waiting period or fee. Candidates should contact IASSC directly or consult the official FAQ for current retake rules. Do not assume a free retake or a specific waiting time; confirm the policy before scheduling a second attempt.
How long is the certification valid?
IASSC certification is recognized perpetually, but under the IASSC Recertification Policy effective March 1, 2017, a classification system recognizes certifications as “Current” for a period of three years and defines regulations for maintaining that status. After three years, you must follow the recertification policy to maintain “Current” status.
How should I prepare and in what order should I study?
IASSC recommends training through a qualified institution, trainer, or corporate program, plus real-world project experience. Study the IASSC Green Belt Body of Knowledge in DMAIC order-Define, Measure, Analyze, Improve, Control-because the exam draws roughly 20 questions from each major section. A non-proctored Green Belt Evaluation Exam is available to help you determine readiness before sitting for the official proctored exam.
What are common failure modes on the exam?
The source does not publish failure-mode data. In practice, candidates should avoid underestimating the breadth of the Body of Knowledge: the exam samples approximately 20 questions from each major section, so neglecting any one DMAIC phase can cost enough points to fall below the 70% threshold. The closed-book, 3-hour format also rewards timed practice and familiarity with both multiple-choice and true/false item styles.