State requirements for the CPA qualification can be summed up as the "Three Es"—Education, Examination and Experience. The education requirement normally must be fulfilled as part of the eligibility criteria to sit for the Uniform CPA Exam. The examination component is the Uniform CPA Exam itself. Some states have a two-tier system whereby an individual would first become certified—usually by passing the Uniform CPA Exam. That individual would then later be eligible to be licensed once a certain amount of work experience is accomplished. Other states have a one-tier system whereby an individual would be certified and licensed at the same time when both the CPA exam is passed and the work experience requirement has been met.