You can retake the exam for the same cost, unless you purchased CCNA Exam Safeguard. However, there is a wait period between the original attempt and a retest:If you fail an Entry, Associate, Professional, Specialist or CCDE Written exam, you must wait five calendar days, beginning the day after the failed attempt, before you can retest for the same exam.If you fail an expert-level lab or practical exam, you must wait 30 calendar days, beginning the day after the failed attempt, before you can schedule for the same exam.If you fail an online, unproctored Cisco (700-xxx series) exam, you must wait 48 hours after the failed attempt before you can retest for the same exam.You must wait a minimum of 180 days before taking the same passed Associate, Professional, Specialist, CCDE Written, or online, unproctored Cisco (700-xxx series) exam with an identical exam number.Once you pass any expert-level lab or practical exam, you cannot retake it unless your status becomes “inactive.”