The Mental Health Parity and Addiction Equity Act (MHPAEA) Evaluation Study: Impact on Financial Requirements and Quantitative Treatment Limits for Substance Abuse Treatment among “Carve-In” Plans
Objective: Evaluate whether patient cost-sharing requirements and QTLs for substance use disorders (SUD) became more generous following parity implementation.
Methods: Benefit design data for a sample of large employer group “carve-in” plans (n=3,969 plans and N=12,779 plan-year observations) were obtained from Optum, a national managed behavioral health organization with enrollees in all 50 states. Sampled plans were non-supplemental, self-insured, have calendar year renewal dates and are not collective bargaining plans. Analyses were stratified by whether plans offered in-network benefits only or both in- and out-of-network benefits. We examined changes in financial requirements (copayments and coinsurance by service type and deductibles) and quantitative treatment limits during pre-parity (2008-9), transition to parity (2010), and post-parity (2011-13). We report the proportions of plans with QTLs and with each financial requirement (e.g., what percent of plans require a copayment). Weighted means and standard deviations for each financial requirement are presented among the subsample of plans with that requirement, as well as for all plans. Statistical inferences are based on chi-square and Wilcoxon signed rank test for bivariate analyses as well as two-part model regressions controlling for parity period, employer and plan characteristics, and clustering.
Results: In preliminary results, we found that for the vast majority of plans, medical and behavioral health deductibles were already combined prior to parity. Day and visit limits were quite common prior to parity but were eliminated by the post-parity period. Results for copayments and coinsurance rates were quite mixed in terms of sign and significance. The most consistent result was that in-network copayments for professional services declined post-parity. However, even for this result, the magnitude of the effect was modest. For example, among plans using them, mean pre-parity copayments for professional visits were around $30 (in 2013 $), compared with decreases of around $2-5.
Conclusions: Evidence that MHPAEA led to more generous cost-sharing for specialty treatment for substance use disorders was somewhat mixed. This may be because parity laws are designed to equalize relative generosity of medical and BH benefits rather than achieve a given level of coverage. Results for deductibles and QTLs were less equivocal, with few changes seen with deductibles (because they were already combined prior to parity) and dramatic changes seen with QTLs (which disappeared post-parity).