Once you have got your certified nursing assistant certification there will be a time in the future when you will have to renew it. Mostly the registration should be completed once every two years. There will be a small fee and some paperwork to renew your certification. In order to keep your registration current you will need to complete a refresher course and do a little bit of continuing education and perform a certain number of hours annually. Mostly these days renewal can be done over the phone or internet.