Excerpt: Although the Pension Protection Act ('PPA') of 2006 [P.L. 109-280] permits plan sponsors to continue using the composite long-term corporate bond rate (instead of the 30-year Treasury rate) to calculate their liabilities for minimum funding purposes in 2006 and 2007, it eliminates the rule that allowed sponsors to use a lower interest rate to calculate their maximum deductible contributions in 2004 and 2005.