N.M. Code R. § 3.3.2.8
WITHHOLDING FROM IRREGULAR WAGES
B. If an employer elects to withhold, for federal purposes, a flat percentage of the lump-sum distribution, one-time bonus, fringe benefits and other irregular wages as provided in the Internal Revenue Code, the employer shall withhold a flat percentage for state withholding tax purposes. The flat percentage for state withholding tax purposes shall be a rate equal to the maximum bracket rate set by Section 7-2-7 NMSA 1978 for the taxable year.
[9/8/86, 1/15/97, 12/15/98; 3.3.2.8 NMAC - Rn, 3 NMAC 3.2.8, 12/14/00, A, 10/31/05]