Until the issuance of final regulations, the Agencies have determined that they will establish an enforcement safe harbor under which the Agencies will not take enforcement action against a plan or issuer that divides its benefits furnished on an outpatient basis into two sub-classifications for purposes of applying the financial requirement and treatment limitation rules under MHPAEA: (1) office visits, and (2) all other outpatient items and services. After the sub-classifications are established, the plan or issuer may not impose any financial requirement or treatment limitation on mental health or substance use disorder benefits in any sub-classification (i.e., office visits or non-office visits) that is more restrictive than the predominant financial requirement or treatment limitation that applies to substantially all medical/surgical benefits in the sub-classification using the methodology set forth in the interim final rules. Other than as permitted under this enforcement policy, and except as permitted under the interim final rules for multi-tier prescription drug formularies, sub-classifications are not permitted when applying the financial requirement and treatment limitation rules under MHPAEA. Accordingly, and as stated in the preamble to the interim final rules, separate sub-classifications for generalists and specialists are not permitted.