Lean Six Sigma training
RecommendedIASSC recommends training from a qualified institution, Lean Six Sigma trainer or corporate program.
IASSC Certified Lean Six Sigma Green Belt (ICGB)
Validates knowledge of Lean Six Sigma problem solving, covering DMAIC phases, lean tools and statistical analysis.
Summary
The IASSC Certified Lean Six Sigma Green Belt (ICGB) is one closed-book, proctored exam on the DMAIC method, lean tools and statistics. The certification stays current for three years and renews with a shorter exam rather than the full one.
Good fit if
- You want a Green Belt exam without ASQ’s work-experience rule
- You are happy to study statistics yourself
- You want an exam you can schedule online anytime
Look elsewhere if
- You have three years of work and want ASQ’s name: CSSGB
- You want a project-leader belt: IASSC Black Belt
- You are brand new to improvement work: CSSYB
Salary & jobs
Prerequisites
Cost
What holders say
The projects behind it matter more
Companies with a long Lean Six Sigma history favor ASQ, IASSC and CSSC, but most care more about projects you have delivered. The certification gets the interview; results decide the rest.
Judged by industry
A manufacturing commenter calls Green Belt relevant at entry and mid level, naming ASQ and CSSC as most respected. A healthcare commenter says it raised their salary to over $140,000.
Green Belt before Black Belt
A Master Black Belt says an exam without experience shows only that you learned the theory. Commenters recommend starting with Green Belt and applying it before moving up.
Certification path
IASSC’s Lean Six Sigma exams run Yellow, Green and Black Belt in rising scope.
Renewal
ICGB is Current for 3 years. Renew with a shorter closed-book exam.
- Validity
- 3 years
- Renewal requirement
- Recertification exam, 50 questions in 90 minutes
- Renewal fee
- $268 USD
You need 70% to pass. Take it before your Current status ends or within 90 days after; you get two attempts, at least two weeks apart. If you do not recertify, the status becomes Elapsed and you must pass the full exam again to be Current.
IASSC recertification policy ↗Alternatives
CSSGB$483 required · Intermediate
ASQ’s open-book Green Belt, with three years of experience required.
ICBB$516 required · Advanced
IASSC’s next belt, also exam-only with no prerequisites.
CSSYB$434 required · Entry
ASQ’s entry belt, with no experience requirement.
CAPM$330 required · Entry
Entry-level project management rather than process improvement.
FAQ
How much does the IASSC Green Belt exam cost?
$402 for the exam voucher. A retake needs a new voucher.
Do I need training or experience for the IASSC Green Belt?
No. IASSC recommends training and some real-world experience but requires neither.
Is the IASSC Green Belt exam open book?
No. It is a closed-book, proctored exam of 100 questions in 3 hours, and you need 70% to pass.
Does the IASSC Green Belt expire?
IASSC recognizes the certification perpetually but shows it as Current for three years. Recertify with a 50-question exam ($268) to keep it Current.
Can I take the IASSC Green Belt online?
Yes. You can schedule an online proctored exam at any time, or use a test centre or accredited provider.
What is the difference between IASSC and ASQ Green Belt?
IASSC is a closed-book exam with no experience requirement and renews every three years. ASQ’s CSSGB is open book, requires three years of full-time work and never expires.
Last updated October 2026