Changes in State Laws Related to Coverage for Substance Use Disorder Treatment Across Insurance Sectors, 2006-2020.

Objective: The authors assessed changes in state insurance laws related to coverage for substance use disorder treatment across public and private insurance sectors from 2006 through 2020 in all 50 U.S. states.

Methods: Structured policy surveillance methods, including a coding protocol with duplicate coding and quality controls, were used to track changes in state laws during the 2006-2020 period. The legal database Westlaw was used to identify relevant statutes within each state's commercial insurance (large group, small group, and individual), state employee health benefits, and Medicaid codes. The legal coding instrument included six questions across four themes: parity, mandated coverage, definition of substance use disorders, and enforcement and compliance. Scores were calculated to reflect the comprehensiveness of states' laws and to interpret changes in scores over time.

Results: Comprehensiveness scores across all sectors (on a 0-9 scale) increased, on average, from 1.47 in 2006 to 2.84 in 2020. In 2006, mean scores ranged from 0.47 (state employee sector) to 2.80 (large-group sector) and in 2020, from 1.22 (state employee) to 4.26 (large group).

Conclusions: Comprehensiveness of state insurance laws in relation to substance use disorder treatment improved across all insurance sectors in 2006-2020. The State Substance Use Disorder Insurance Laws Database created in this study will aid future legal epidemiology studies in assessing the cumulative effects of parity-related insurance laws on outcomes of substance use disorder treatments.