; (ii) the applicant is or was a teacher who is using evidence-based alternative certification routes; or (iii) the applicant is a practicing teacher in another field and is pursuing an additional credential in a field in which there is a shortage of teachers, such as mathematics, science, special education, English language acquisition, or another high-need subject. (b) Agreements To serve Each application under subsection (a) shall contain or be accompanied by an agreement by the applicant that— (1) the applicant will— (A) serve as a full-time teacher for a total of not less than 4 academic years within 8 years after completing the course of study for which the applicant received a TEACH Grant under this subpart (referred to in this section as the service obligation window ); (B) teach in a school described in section 465(a)(2)(A); (C) teach in any of the following fields— (i) mathematics; (ii) science; (iii) a foreign language; (iv) bilingual education; (v) special education; (vi) as a reading specialist; (vii) early childhood education; or (viii) another field documented as high-need by the Federal Government, State government, or local educational agency, and approved by the Secretary; and (D) submit evidence of such employment in the form of a certification by the chief administrative officer of the school upon completion of each year of such service; (2) in the event that the applicant is determined to have failed or refused to carry out such service obligation, an amount (which shall be a pro-rated amount for partial service) of any TEACH Grants received by such applicant will be treated as a loan and collected from the applicant in accordance with subsection (c) and the regulations thereunder