N.M. Admin. Code § 2.81.8.10
An independent public employer that chooses to become a participating employer after December 31, 1997, shall submit their opt-in ordinance or opt-in resolution to the NMRHCA board prior to the board's semi-annual review meeting. Following acceptance by the NMRHCA board, the employer shall begin making employer and employee contributions to the fund in an amount determined to be appropriate by the NMRHCA board on the January 1 or July 1, immediately following the adoption of the ordinance or resolution. On the following January 1 or July 1, eligible retirees of those participating employers and their eligible dependents shall be eligible to receive group health insurance coverage pursuant to the provisions of the Retiree Health Care Act.
N.M. Admin. Code § 2.81.8.10