I think you need to retake the test. According to Missouri's laws and regulations, if your CNA status is active and in good standing on another state's registry, then you are eligible to sit for the nursing assistant exam. You must submit a written request to the Department of Health and Human Services as well as the following information and copies of these documents: your out-of-state CNA certificate, social security card, return address, phone number where you can be reached, and employment verification of eight hours of work for every two years from the date when you became certified in your current state. If the state where you are certified (Nebraska) keeps track of your employment then you do not need to submit the work verification documents. You should call the Missouri nurse aide registry to ensure this is the correct process and to ask any questions you might have on completing the required applications.