; or (ii) not include any aggregate lifetime limit on mental health or substance use disorder benefits that is less than the applicable lifetime limit. (C) Rule in case of different limits In the case of a plan or coverage that is not described in subparagraph (A) or (B) and that includes no or different aggregate lifetime limits on different categories of medical and surgical benefits, the Secretary shall establish rules under which subparagraph (B) is applied to such plan or coverage with respect to mental health and substance use disorder benefits by substituting for the applicable lifetime limit an average aggregate lifetime limit that is computed taking into account the weighted average of the aggregate lifetime limits applicable to such categories. (2) Annual limits In the case of a group health plan or a health insurance issuer offering group or individual health insurance coverage that provides both medical and surgical benefits and mental health or substance use disorder benefits— (A) No annual limit If the plan or coverage does not include an annual limit on substantially all medical and surgical benefits, the plan or coverage may not impose any annual limit on mental health or substance use disorder benefits. (B) Annual limit If the plan or coverage includes an annual limit on substantially all medical and surgical benefits (in this paragraph referred to as the applicable annual limit ), the plan or coverage shall either— (i) apply the applicable annual limit both to medical and surgical benefits to which it otherwise would apply and to mental health and substance use disorder benefits and not distinguish in the application of such limit between such medical and surgical benefits and mental health and substance use disorder benefits