By comparison, the majority of mutual fund investing for Baby Boomers is outside of an employer-sponsored retirement plan, Investment Company Institute data shows.
Twenty-two percent do not know how their assets are invested, Legg Mason found in a survey.
However, 82% of Millennials say their financial planning needs improvement.
Only 21% of non-investing Millennials and Millennials with only retirement accounts are very or extremely confident about making investment decisions.
A Charles Schwab self-directed brokerage account (SDBA) report found that Gen Xers and Baby Boomers allocated less to their exchange-traded funds (ETFs) than the younger age group.
And they generally think they will need to save half of what Baby Boomers think is needed to retire comfortably.
While 27% of Millennial Americans allocate more cash towards coffee than retirement savings, most save an average of $480 per month on retirement.
Most Millennials are appropriately invested, with 90% of their portfolios in equities.
They also value financial planning more than a bonus.
Ryan Bailey, head of the Retail Banking Group, Bank of the West, offers tips for plan sponsors to help educate Millennials about the importance of investing.
The women are also far more risk-averse, PNC Investments learned in a survey.
But, TD Ameritrade finds only 38% are saving for retirement.
More than one-quarter of Millennials have more than $100,000 in retirement savings, with an average of 30 to 35 years before retirement, compared to 75% of Boomers with more than $100,000 in savings and an average of only three years before retirement.
Seventy-nine percent believe that by the age of 80, a comfortable retirement will be a thing of the past, and 70% say that is because they are unable to save as much as retirement planning tools recommend.
A report from the National Institute on Retirement Security shows that 66.2% of working Millennials have nothing saved for retirement.
Nearly six in ten believe saving for retirement is a basic necessity, like food or housing, a survey from Allianz Life found.
However, researchers say their outcome could possibly improve, given the fact that they still have a long time horizon to save, the markets could deliver strong returns and the government could save Social Security.
Forty-three percent of Millennials say they need help managing saving for retirement, while 40% want help with good general savings habits.
One-third would sacrifice retirement benefits.