You can't talk about 401(k)s for three days without eventually coming around to target-date funds. They're offered in 70 percent of defined contribution plans and are expected to account for 70 percent of all assets in DC plans by 2020, according to speakers at a session during the 2013 NAPA/ASPPA 401(k) Summit.

TDFs' "explosive growth masks the fact that they are still in their infancy," Rich Weiss, senior vice president and senior portfolio manager of American Century Investments, told attendees on March 4. "Most funds were launched in the last five or 10 years, but there's a dearth of real-time data." With no industry-accepted standard benchmark, many providers produce their own, he said.

Typical measures of a TDF are to examine the equity allocations at retirement or count the number of asset classes in the fund, but Weiss said these were best undertaken by an independent third party. A more sophisticated measure is to look at the underlying portfolios using both historical and forecasted performance data, he suggested. When evaluating the overall risk of the series, advisors should incorporate the entire lifespan of the fund, he said.