Third quarter data for defined contribution plans administered by MassMutual shows that, combined, Gen X and Gen Y participants now account for 55 percent of the company’s participant count, compared to 41 percent of Baby Boomer participants.

Baby Boomers still control the lion’s share of assets at 61 percent, with the combined Gen X/Gen Y group holding 31 percent of all defined contribution plan assets on MassMutual’s platform.

The percentage of MassMutual’s total participant assets in age-based and risk-based options reached an all-time high during the third quarter of 2012, accounting for 26.6 percent of total defined contribution plan assets under management, which is well above the industry average. Gen Y participants born between 1982 and 1995 led with 49.8 percent for the quarter compared to Gen Xers born between 1965 and 1981 at 29.8 percent and Baby Boomers at 22.6 percent. Significantly, Gen X participants had the highest allocations in equities at 45.6 percent for the quarter ended Sept. 30, compared with Gen Y savers at 32.2 percent and Baby Boomers at 38.4 percent.

"Not surprisingly, Gen Y savers are taking full advantage of asset allocation investment options," said Elaine Sarsynski, executive vice president of MassMutual’s retirement services division, said in a statement. "We are so pleased to see that younger generations appear to understand the importance of starting early to save for retirement."