Between the networking, the interviewing, the negotiating, and the onboarding, moving on or up can feel like a job of its own.

Americans are as eager to work as ever. Just no longer for somebody else.

According to FreshBooks, a cloud-based accounting company that has conducted a study on self-employment for two years, the number of Americans working for themselves looks to triple—to 42 million people—by 2020.

The trend, gauged in a survey of more than 2,700 full-time US workers in traditional, independent, and small business roles about their career plans, is largely being driven by millennial workers. FreshBooks estimates that of the next 27 million independent workers, 42% will be millennials. The survey, conducted with Research Now, also finds that Americans who already work for themselves are suddenly very content to keep doing so, with 97% of independent workers (up 10% from 2016) reporting no desire to return to traditional work.

“Americans are increasingly disillusioned with the notion that a successful career means climbing the corporate ladder,”FreshBooks CEO Mike McDerment told Quartz. “Whether or not the shift to self-employment occurs at the velocity our study indicates or not, the real significance is the mindset shift of the American workforce.”

What’s changed? Self-employment is no easy career route—but the idea has gotten more popular of late thanks to the modern economy’s splintering of traditional jobs into freelance work and temporary work, and to the come-and-go roles of the gig economy. Despite its lack of financial security, independent work also offers psychological benefits of creativity and autonomy. Studies have shown that most people actually prefer autonomy to authority and prestige.

FreshBooks’ report isn’t the first of its kind—by other estimates, almost half the American workforce will be freelance by 2020—but the growing number of such studies reinforces the point that what was once speculation is now a near-certain trend.