Ariz. Rev. Stat. § 38-766
A. A retired member who is engaged to work by an employer for at least twenty weeks in each fiscal year and at least twenty hours per week resumes active membership in ASRS. ASRS shall suspend payment of the member's retirement benefits until the member either:
D. Notwithstanding subsection A of this section, ASRS shall not suspend the payment of retirement benefits if a retired member begins or returns to employment with an employer in a position that satisfies all of the following:
2. Either:
G. An employer that engaged the retired member to work pursuant to this section shall pay to ASRS an amount equal to the rate established by the actuary pursuant to section 38-766.02, subsection B for the period starting with the first day the retired member began working after retirement through the earlier of: