New Mexico Statutes Chapter 22. Public Schools § 22-11-16.2. Substitutes; membership status

An employee engaged on a day-to-day basis to replace another employee who is temporarily absent shall be considered a substitute and shall not be covered under the Educational Retirement Act. An employee engaged to fill a vacant position, including a position vacated by a leave of absence of at least ninety days, shall not be considered a substitute and is subject to the requirements of the Educational Retirement Act.