They aren't leaving the nest.
More than one-third of millennials still live with their parents, the highest share in their age group in at least 40 years, according to a Pew Research Center analysis released Thursday.
Last year, a record 21.6 million adults ages 18-31 lived in their parents' homes, Pew said. That's up from 18.5 million in 2007.
The reasons why millennials are living with their parents vary, Pew said. It's a combination of economic, educational and cultural factors.
But one striking detail shows that men are more likely than women to still be living with their parents, according to Thursday's analysis.
About 40% of millennial men are living at home, compared with 32% of women in the same age group.
Unsurprisingly, the recession played a large role in increasing this type of living arrangement. Unemployed millennials are more likely to live at home.
According to Pew, 63% of millenials held jobs in 2012 -- that's down from 70% for the 18-31 age group in 2007.
The report also showed that younger adults, age 18 to 24, were more likely to live at home than those 25 to 31. The data show that 56% of the younger subset lived at home versus 25% of the older group.
Educational attainment levels also played a role in whether a millennial lived at home, Pew said. Only 18% of those with a four-year degree lived at home compared with 40% of those who only had a high school education.