(a) Except as provided in (c) or (d) of this section, a teacher acquires tenure rights in a district when the teacher

(1) possesses a valid teaching certificate that authorizes the teacher to be employed as a certificated teacher or as an administrator under regulations adopted by the department;

(2) has been employed as a teacher in the same district continuously for three full school years;

(3) receives, in the third year of any three-year period of continuous employment with the district, an evaluation under the district's evaluation system stating that the teacher's performance meets the district performance standards; and

(4) on or before October 15 of the school year,

(A) accepts a contract for employment as a teacher in the district for a fourth consecutive school year; and

(B) performs a day of teaching services in the district during that school year.

(b) In this section, a full school year of employment means employment that begins on or before the first student count day required by the department in a school year or October 15, whichever occurs first, and continues through the remainder of the school year.

(c) A superintendent may not acquire or maintain tenure in a district.

(d) A teacher who has acquired tenure in a school district in the state and who loses tenure in the district because of a break in service may reacquire tenure in that school district under this subsection if the break in service was not the result of a dismissal under AS 14.20.170 or nonretention under AS 14.20.175 and did not last longer than one year. A break in service that begins on or after the last day of a school district's instructional days for a school year but before the first instructional day of the next school year will be considered to have lasted no longer than one year if the teacher is employed on the first instructional day of the school year that begins more than 12 but not more than 16 months after the beginning of the break in service. A previously tenured teacher reacquires tenure in the school district under this subsection when the teacher

(1) possesses a valid teaching certificate that authorizes the teacher to be employed as a certificated teacher or as an administrator under regulations adopted by the department;

(2) has been employed as a teacher in the district continuously for one full school year after a break in service that does not exceed the time limits set out in this subsection;

(3) receives, under the district's evaluation system, an acceptable evaluation from the district; and

(4) on or before October 15 of the school year,

(A) accepts a contract for employment as a teacher in the district for a second consecutive school year; and

(B) performs a day of teaching services in the district during that school year.

(e) Notwithstanding (a) of this section, a teacher who has acquired tenure in a school district who moves to a new school district acquires tenure in the new school district on the first instructional day of the third year of employment in the new school district if

(1) the teacher otherwise meets the qualifications for tenure set out in (a) of this section; and

(2) the break in service meets the requirements of (d) of this section.