An individual who completes a nurse aide training program in Arizona has two years from the graduation date to register and take the certification exam. Eligibility to take the exam is lost if one does not sit for the exam within two years of completing the training. One exception to this rule is when the individual can show proof of work as a nursing assistant for one-hundred and sixty hours every two years since completing the training course. The work hours need to be verified in writing by the employer.