(a) A student who has already earned a research doctoral degree at any public or private post-secondary institution is ineligible to participate in the Program.(b) Unless granted a hardship postponement in accordance with §22.309 of this subchapter (relating to Hardship Provisions), a student's eligibility for a grant ends:(1) Four years from the start of the semester in which the student enrolls in the research doctoral degree program at the eligible institution; or(2) If a Research Scholar transfers to another institution.