(a) If a teacher who has acquired tenure rights is to be laid off under AS 14.20.177 or is not to be retained for the following school year, the employer shall notify the teacher of the layoff or nonretention by writing, delivered before May 15, or by registered mail postmarked before May 15.
(b) If a teacher who has not acquired tenure rights is to be laid off under AS 14.20.177 or is not to be retained for the following school year the employer shall notify the teacher of the layoff or nonretention by writing delivered on or before the last day of the school term or by registered mail postmarked on or before the last day of the school term.
(c) Notwithstanding a teacher's right to continued employment under AS 39.20.500 - 39.20.550, a school district may notify a teacher of layoff or nonretention under this section for the following school year for a permissible reason.