The Mental Health Parity and Addiction Equity Act (MHPAEA) Evaluation Study: Impact on Quantitative Treatment Limits

The Mental Health Parity and Addiction Equity Act (MHPAEA) significantly changed regulations governing behavioral health benefits for large, commercially insured employers. Pre-MHPAEA, many plans covered only a specific number of behavioral health treatment days or visits; post-MHPAEA, such quantitative treatment limits (QTLs) were allowed only if they were "at parity" with medical-surgical limits. This study assessed MHPAEA's effect on the prevalence of behavioral health QTLs.

Analyses used 2008-2013 specialty behavioral health benefit design data for Optum large-group plans, both carve-outs (N=2,257 plan-years, corresponding to 1,527 plans and 40 employers) and carve-ins (N=11,644 plan-years, 3,569 plans, and 340 employers). Descriptive statistics were calculated for limits existing at parity implementation, distinguished by accumulation period (annual or lifetime), level of care (inpatient, intermediate, or outpatient), unit (days, visits, or courses), condition, and network level. Proportions of plans using specific limits during the preparity (2008-2009), transition (2010), and postparity (2011-2013) periods were compared with Fisher's exact tests.

Preparity, the most common QTLs were annual visit or day limits. Accounting for overlap in limit types, 89% of regular carve-out plans, 90% of in-network-only carve-outs, and 77% of carve-in plans limited outpatient visits; 66% of regular carve-out plans, 74% of in-network-only carve-outs, and 73% of carve-ins limited inpatient or intermediate days. Postparity, QTLs almost entirely disappeared (p<.001).

Before MHPAEA, QTLs were common. Postimplementation, virtually all plans dropped such limits, suggesting that MHPAEA was effective at eliminating QTLs. However, increasing access to behavioral health care will mean going beyond such QTL changes and looking at other areas of benefit management.