You may retake the quiz as many times as necessary to pass it at no additional charge for a period of up to one year after the date of course purchase. All courses and quizzes must be completed before the end of your subscription period or your access to the course is lost, and a certificate of completion will not be issued. Partially completed courses will remain available up to one year if a membership is renewed without lapse. You must earn a passing score of 70% or higher in order to receive a certificate of completion.