(a) The tribe may continue to provide foster care services on a voluntary basis to a youth in tribal custody who turns 18 prior to completing his or her:
(b) One month prior to the youth's 18th birthday, the tribal Child Welfare (CW) worker provides to the CW tribal liaison:
(c) The youth:
(d) The tribal CW worker assists the youth in applying for Title XIX medical benefits as soon as possible after the youth's 18th birthday.