The Society of Actuaries Retirement Plans Experience Committee (RPEC) published an October 2014 study analyzing mortality experience of uninsured private defined benefit pension plans in the United States for the period 2004 through 2008. It is referred to as the RP-2014 mortality table report. RP-2014 replaces RPEC's RP-2000 mortality tables published in July 2000.

While the RP-2014 report may imply there is only one mortality table, there are several mortality tables published within the report. A companion report was concurrently published detailing a mortality projection scale, referred to as the MP-2014 improvement scale. Because mortality studies are not completed all that frequently, mortality improvements scales are developed to be used in conjunction with a mortality table to project future mortality improvements.

Since the release of the two RPEC reports, defined benefit pension plan sponsors felt compelled to reflect the longer life expectancies in the determination of defined benefit plan liabilities for financial disclosures. For those plan sponsors that elected to change the plan's mortality assumption to RP-2014 with projection scale MP-2014, it generally increased the plan's liability between 4% and 10%. The impact on a plan was dependent on that plan's demographics as well as on the mortality table that was previously used.

RPEC published a revised mortality improvement scale in October 2015, appropriately labeled MP-2015. Additional mortality data published by the Social Security Administration (SSA) was used for the new calculation.

RPEC had indicated within the MP-2014 report that it intends to publish updated improvement scales at least triennially. However, an updated report issued one year after RP-2014 was a surprise to defined benefit pension plan sponsors, as well as many pension actuaries.

The MP-2014 mortality improvement scale was constructed based on a model developed by RPEC utilizing SSA mortality data between 1950 and 2009. The MP-2015 mortality improvement scale incorporates two additional years of SSA data (2010 and 2011). The SSA data indicates that mortality rates remained relatively constant for 2010 and 2011. This is in contrast to the expectations of the MP-2014 calculations, which predicted mortality improvement for this period. Plans that utilized the RP-2014 mortality table with MP-2014 mortality improvement scale may see a 0% to 2% decrease in plan liabilities by utilizing the MP-2015 mortality improvement scale in their fiscal year-end financial disclosures.

The SSA has recently released two additional years (2012 and 2013) of mortality data, which again indicate that the mortality rates are not decreasing as significantly as expected. In fact, this newly released data suggests that mortality rates have been stagnant over the last five years. The RPEC committee has indicated that it intends to issue future periodic updates to the model as soon as practicable, following the public release of updated data upon which the model is constructed.

The question is when will a new mortality improvement scale, reflecting the latest SSA data from 2012 and 2013, be released? Will RPEC issue MP-2016, a new mortality improvement scale reflecting the latest SSA mortality data?

The MP-2015 report states that RPEC will not publish any additional information before the second quarter of 2016. Unfortunately, because of the timing of the release, a new mortality improvement scale (MP-2016 potentially) will not be available for disclosures with fiscal years ending in 2015. However, the updated mortality improvement scale may be able to be incorporated into the net periodic pension expense determination for fiscal years ending in 2016. This will be dependent on the timing of the RPEC analysis and publication, as well as approval by the plan sponsor's auditor.