An APRN with fewer than 24 months and 2,400 hours of licensed active advanced nursing practice in an initial role and population focus or fewer than 12 months and 1,600 hours for any additional role and population focus shall have a formal agreement with a collaborating provider as required by Board rule. An APRN required to practice with a collaborative provider agreement may not engage in solo practice, except with regard to a role and population focus in which the APRN has met the requirements of this subsection.