This means that Norwegians are able to keep their Norwegian citizenship if they become citizens of another country. Those who have lost their Norwegian citizenship under the old rules because they became citizens of another country will be able to reclaim it.
To reinstate your Norwegian citizenship, you will need to submit an online application form at UDI.no and pay the application fee, then attend an appointment with the Norwegian Embassy (in Washington DC) or a consulate general (in New York, Houston or San Francisco) to hand in the documents needed to process your application.
Please note that the rules regarding retention of citizenship for children born abroad to a Norwegian parent have not changed. If you were a dual citizen as a child, and did not spend at least 6 months in Norway before you turned 22, you will not be able to reclaim your Norwegian citizenship.
Read more about obtaining dual citizenship at the Norwegian Directorate of Immigration (UDI) websites. UDI is the central agency in the Norwegian immigration administration, and can answer questions about the citizenship rules.
Are you wondering whether you already are a Norwegian citizen? Answer the questions in this guide: https://www.udi.no/en/word-definitions/are-you-a-norwegian-citizen/