I believe it is 20 CEUs every 2 years, but you should call them and double check this.
That is a good thing, as a cert. that does not require continuing education is not going to command the same respect as one that does.
Do check the accreditation. The last I had heard it was not NCCA accredited. This may have changed, and the places you want to work may not care, but a lot of places do.
It also used to have an in home test. You might also want to look into that. A proctored test is better, as it is more rigorous, and again holds weight with some people.
If you are planning to coach online you may not have as many questions of what employers are looking for, but you do want to look into what is legally required to do what sort of nutrition coaching in your state.