An Access System can provide identity management and/or access management services. Examples of access management services include authentication and authorization services. In some implementations, users of an Access System want to use the authorization services of the Access System but do not want to use the authentication services of the Access System. The present invention allows some or all of the resources protected by the Access System to use the authentication services of the Access System and some or all of the resources protected by the Access System to use external authentication services.