N.M. Admin. Code § 3.4.1.11
For a corporation filing a separate return for taxable years beginning before January 1, 2020 and for a corporation that is not part of a unitary group or is required to file a separate return under Regulation 3.4.10.16 for taxable years beginning on or after January 1, 2020, that corporation's base income base income shall be determined by completing a simulated federal corporate income tax return for the separate corporation. In completing the simulated federal return, only the income and expenses of the separate corporation will be allowed. The simulated return shall be prepared as if the corporate entity were filing a federal return as a separate corporation and not as a corporation included in a consolidated return. All provisions of the Internal Revenue Code which would apply to the filing as a separate corporation shall apply to the completion of the simulated return. Procedures and adjustments allowed by the Internal Revenue Code which apply to the filing of a federal consolidated return concerning the elimination of intercompany transactions or the sale or dissolution of one of the corporations within the federal consolidated group shall not be allowed when completing the simulated federal return for New Mexico income tax purposes. In no case shall a net operating loss established for the corporation reporting on a separate corporation basis be excluded from the base income of any other corporation or from the base income reported on any combined or consolidated return for any group of corporations except as a net operation loss carryover deduction to the extent allowable under Section 7-2A-2 NMSA 1978, and applicable federal limitations.
N.M. Admin. Code § 3.4.1.11