Millennials, the generation born between 1981 and 1999, now make up the largest segment of the U.S. workforce, with an estimated 53.5 million workers. (Matt McClain/The Washington Post)

If the stereotypes are to be believed, millennials are a group of downtown-dwelling, bike-sharing, 20- and 30-somethings who would rather drink craft beer than get married.

But that’s not the full story, according to a report being released Wednesday by American University’s Kogod School of Business.

Nearly 40 percent of millennials in the Washington region are married, and an additional 15 percent are unmarried but living with a significant other, according to the study. About 60 percent of them regularly drive to work, triple the number of respondents who commute using Metro.

For all the talk of millennials and their propensities, researchers found they aren’t all that different from their parents: They want job security. They want to get married, buy homes, find affordable child care and drive to work, according to the 2016 Millennial Index.

And increasingly, they are finding that high housing prices and lengthy commutes in the Washington area are getting in their way.

“There are a lot of anecdotal stories about millennials wanting to do bike share and wanting salad bars downstairs, but we realized there was no good data on millennials in Washington,” said Erran Carmel, dean of the Kogod School. “What we found was a bit contrarian.”

Millennials, the generation born between 1981 and 1999, now make up the largest segment of the U.S. workforce, with an estimated 53.5 million workers. Their presence is expected to become even larger in the coming years as more graduate from school and find jobs.

They are potentially an economic powerhouse, and attracting and retaining a steady stream of young professionals can be crucial to remaining competitive, said James C. Dinegar, president and chief executive of the Greater Washington Board of Trade, which co-sponsored the study with Kaiser Permanente.

“If you’re just a rank-and-file company with X number of days off and no flexibility, you can move to the back of the line,” Dinegar said. “There are higher and different expectations now.”

Millennials flocked to the Washington area during the Great Recession, lured by the promise of a stable job market and high salaries. But data suggests that growth may be stalling as the high costs of living and gridlocked traffic weigh on millennials’ minds.

To stay competitive, Washington businesses need to find ways to address millennials’ top concerns, which include high housing costs, a lack of affordable child care and lengthy commutes, says Dawn Leijon, the report’s author and executive in residence at the Kogod School.

“It can be things like, how do we help people have more flexible work hours? Or how do we set up jobs to have telecommuting one day a week?” Leijon said. “ Or they could find creative benefits, such as ‘Hey, you work for us for five years, and we’ll give you X amount of money for a down payment.’ ”

The Millennial Index was calculated by asking 300 adults ages 20 to 34 about the importance of 31 factors — from housing costs to volunteer opportunities and international population — and then asking them to grade the Washington area on those factors.

According to the index, the Washington area has a millennial-friendly score of 1.25, meaning it is 25 percent more attractive than the average U.S. city. The Kogod School plans to measure millennial sentiment annually.