And many millennials are still living with their parents, 1 in 3, according to Market Watch.
But why are they delaying moving from post-teenage living to adulthood?
More than half are blaming student loans, Bankrate.com found.
Some are also still learning, still enrolled in school, Market Watch found. About 8 percent of the millennial population are still cracking the books in their 30s.
[Source: U.S. Census Bureau]