On October 1, 2015, a new Massachusetts law went into effect requiring health plans to cover acute treatment and clinical stabilization for substance use disorder for 14 days without prior approval. Medical necessity for either or both services will be determined by the treating clinical professional. Insurers can initiate utilization review procedures on day seven. The provisions affect new or renewed policies issued on or after October 1, 2015 by commercial fully insured health plans, and fully insured and self-insured plans operated by the Massachusetts Group Insurance Commission (GIC) for state and local employees. The provisions do not apply . . .