(1) A member may apply to purchase creditable service for employment outside the United States or its possessions in a federal, public or private school if it is an organized, existing institution established and operated for the purpose of instructing students.

(2) A member must provide adequate documentation to permit the board to reasonably ascertain:

(a) if the services performed would be eligible for membership under the teachers' retirement system had they been performed in Montana and;

(b) if the school is a qualified institution established for the purpose of instructing students.