N.M. Stat. § 59A-18-13.6
Pooling of closed blocks of business.
For the purpose of determining the rate of any policy within a closed block of
business, the superintendent may require an insurer to pool the experience of a closed
block of business with all appropriate blocks of business that are not closed in
accordance with Section 59A-18-13.1 NMSA 1978. An insurer shall not apply a rate
penalty or surcharge beyond that which reflects the experience of a pool combined in
accordance with this section.