Individuals who have been admitted to discrete psychiatric units of hospitals licensed pursuant to article 28 of the Public Health Law, residential treatment facilities for children and youth, or individuals 21 years of age of less or 65 years of age or older who are receiving services at State-operated psychiatric facilities or hospitals licensed pursuant to article 31 of the Mental Hygiene Law and who have an anticipated discharge within 90 days or less, may receive case management services. Such services shall be billed pursuant to the standards established in sections 506.5, 506.6 and 506.7 of this Part, if such services are required in order to facilitate the process of transition to community services and to enable the individual to gain access to needed medical, social, educational, and other services in the community.