If you have had continuous legal residence in Norway as an EEA national for at least five years, you can apply for permanent right of residence. The document certifying permanent legal residence is issued on application and it is valid indefinitely. In some cases, you can be granted permanent right of residence if you have stayed in Norway for a shorter period.
If members of your family have had continuous legal residence in Norway may also be entitled to permanent residence, regardless of their citizenship. It is required that you have lived together in Norway during those five years.