Mont. Code Ann. § 39-51-1216
39-51-1216 Experience rating record voided when account inactive
39-51-1216 . Experience rating record voided when account inactive. An employer who has not had covered employment or whose coverage has been terminated because the employer has ceased to do business for 5 consecutive years is considered a new employer and may not be credited with the employer's previous experience for the purpose of computing any future "experience factor".