Is a target-date fund for you?

A quiet revolution is sweeping through the mutual fund world. Over the past few years, target-date funds -- prepackaged retirement funds with a mix of stocks and bonds that adjust to become more conservative as you age -- have begun reshaping the retirement landscape.

Target-date funds are gobbling up money as increasing numbers of 401(k) plan administrators default employees into them: At year-end they accounted for $481 billion in assets, well more than double the $183 billion they had in 2007, according to the Investment Company Institute. Moreover, last year nearly two-thirds of the money flowing into defined-contribution plans went to target-date funds, according to Callan Associates. "Most people in the industry are envisioning that target-date funds eventually will have the majority of assets," says Lori Lucas, who oversees Callan's defined-contribution practice. "People don't know what else to do with their money."