The aggregate funded status of defined benefit plans of S&P 1500 companies improved to 83% in May, up one percentage point from April and up nine percentage points from January, a Mercer report said.
Rising interest rates and equity markets resulted in the monthly funding increase, Mercer said.
In May, the discount rate rose 19 basis points to 3.99%, while the S&P 500 index gained 1.1%. The MSCI EAFE index, by comparison, fell 1%.
Mercer's estimated aggregate plan assets totaled $1.89 trillion as of May 31, compared to estimated aggregate liabilities of $2.27 trillion. The previous month, the estimated assets and liabilities were $1.9 trillion and $2.32 trillion, respectively.
“The trend of improvements in funded status since the end of January 2015 continues in May as interest rates rise above 2014 year-end levels and equity markets hold steady,” said Jim Ritchie, a principal in Mercer's retirement practice, in a news release. “We are seeing many plan sponsors lock into these gains by executing risk transfer strategies like vested terminated cashouts and annuity purchases.”