Headlines often laud the millennial generation's propensity to stash away money for  long-term goals, but when recent research has looked more deeply at how millennials save, it seems that they’re eschewing tax-deferred retirement plans and investing in favor of holding their assets in savings accounts as cash.

That may be because 401(k) plans don’t appeal to millennial needs, says Kevin Boyles, senior vice president at Dresher, Pa.-based Ascensus, a provider of retirement, educational and health saings plans.

“Of course it’s dangerous to generalize 70 million to 90 million people, but all of the data that I’ve seen shows that millennial savers are better than any other generation post Great Depression,” Boyles says. “Incentive to save isn’t the problem, it’s incentive to invest and an investment vehicle that meets their needs.”

Boyles says that for younger, low-asset millennials entering the workforce, a Roth IRA can double as a long-term retirement account and a medium-term rainy day fund.

“The Roth gives an opportunity for these younger, lower-income millennials to plant a seed right out of college,” Boyles says. “There’s also am opportunity for advisors who want to talk to these people while they have relatively few assets and small needs , a chance to capture a growing demographic segment that stands to inherit $40 trillion in wealth over the next few decades.”

A recent Bankrate.com report showed that almost 40 percent of those under 30 choose cash as their preferred way to save money they won’t need for at least ten years, while additional research from TD Ameritrade found that 47 percent of millennial respondents believed a savings account was the best way to prepare for retirement.

According to the 2015 Generational Research Report, a collection of data from El Segundo, Calif.-based researcher Financial Finesse, millennials were the least likely of all generations in the U.S. workforce to contribute to a workplace retirement plan, and their participation rate is declining. In 2015, 34 percent of younger millennial workers aged 21 to 27 reported participating in a defined contribution plan, down from a 40 percent participation rate in 2015.

That decline may be because many millennials now entering the workforce are self-employed or working as contract employees, says Boyles.

“Consider that millennials are the most entrepreneurial generation that we’ve seen for some time, even those who aren’t necessarily starting their own businesses are still working for themselves,” Boyles says. “We estimate that somewhere around 24 percent of millennials are non-W-2 workers. A lot of them are in Silicon Valley. So right of the bat, one-in-four millennials don’t have access to an employer retirement plan.”

Younger workers’ longer time horizon means that they face more potential contingencies that might require emergency savings, says Boyles, so some are delaying contributing to retirement accounts to build up their rainy-day funds. Millennials, generally more likely to move between geographic locations or employers than older generations, also need their accounts to be liquid and mobile.