After the publication of the Milliman Healthcare Reform Briefing Paper "Implementing Parity: Investing in Behavioral Health" (available at http://publications.milliman.com/publications/healthreform/pdfs/implementing-parity-investing-behavioral.pdf) in May 2010, the U.S. Department of Labor issued new guidance for compliance with the 2008 Mental Health Parity and Addiction Equity Act (MHPAEA) that will apply to many group health plan sponsors and issuers of group health plan insurance. This issue brief provides some details on DOL's guidance, including the temporary safe harbor provision.