The Treasury Department, Department of Labor, CMS and HHS published interim final regulations under the Paul Wellstone and Pete Domenici Mental Health Parity and Addiction Equity Act of 2008 on February 2, 2010. The regulations apply to plan years beginning on or after July 1, 2010 – meaning January 1, 2011, for calendar year plans. As explained in our November 11, 2008 Update, the Act extended the parity requirements for mental health benefits to include substance abuse benefits, and to require parity not only with respect to annual and lifetime limits but also "financial requirements" (including deductibles, copayments, coinsurance, and out-of-pocket expenses) and treatment limits (frequency of treatment, number of visits, days of coverage, or other similar limits on the scope or duration of treatment). The regulations interpret these requirements broadly and will require many companies to make significant changes to their health plans and record-keeping systems. Companies that are not already reviewing their plans for compliance with the new requirements should consider doing so in order to make any required changes by the deadline.