This is pulled straight from the committee report:
Provision: The corridor on interest rates would remain at ten percent through 2019. The corridor would increase by five percent per year through 2023, at which point the corridor would remain permanently at 30 percent. The provision would generally be effective for plan years beginning after December 31, 2015. This proposed reduction in required pension contributions would, purely at the discretion of employers that choose to take advantage of this pension funding relief, result in those employers having more taxable income (because the contributions that they elect to defer are tax-deductible when contributed). This is estimated to increase revenues as compared to the budget baseline. It is also estimated to result indirectly in increased Pension Benefit Guaranty Corporation (PBGC) premiums because employers that, purely at their discretion, choose to take advantage of this funding relief would have a larger base for purposes of computing the variable rate premium on underfunding.
Nothing we didn't already know, but Congress cant plead ignorance when they put in their reports that they are knowingly allowing employers to underfund their plan and consider it to be a good thing because it will increase PBGC revenue. All they mention is the increase in PBGC revenue. No mention of the larger increase in long term liability caused by the underfunding. Just disgusting...