Up until the ‘call for full members’ launch date (expected September 2019), member states can designate ‘affiliated partners’. Affiliated partners are not members of an ERN and they are not required to meet the same criteria. Furthermore, if a member state already has a healthcare provider involved in the network as a full member, they cannot designate an affiliated partner. Affiliated partners are expected to provide a link to the ERN for those European countries without a healthcare provider involved. They thus address the concerns related to the geographic coverage of the networks.
Affiliated partners may at a later stage, if they are healthcare providers and have the required expertise, become ERN members (in compliance with the procedures for membership applicable to any healthcare provider)
More information on affiliated partnership and the application process can be found here