The growth of the gig economy will continue, according to a new report from Betterment, “Gig Economy Workers and the Future of Retirement.” Today, more than one in three workers are freelancers, and that is expected to grow to 40% by 2020.

Additionally, 16% of Americans are planning on taking on a gig job in retirement to supplement their earnings. Twelve percent of those who currently have a gig job in addition to a full-time position are planning on keeping that gig job in retirement, and many say that the gig will be their main source of income. Among those who are full-time gig workers, 20% are planning on continuing some type of gig work after “retiring.”

However, 81% of gig economy workers say that debt is a big reason why they cannot prioritize saving for retirement. While 59% of gig workers use a digital platform for their job, only 19% use a digital platform for saving, and 28% use one for online investing.

“The emergence of the gig economy has changed the American workforce, and the way we save for retirement needs to change with it,” says John Stein, CEO of Betterment. “At Betterment, we’re helping investors prepare for this shift by providing solutions that go well beyond simply low-cost IRAs [individual retirement accounts], by lowering costs and making investing accessible for everyone. It’s time for lawmakers to do the same by introducing a modern framework that gives non-traditional workers financial stability for the future.”

Betterment conducted the online survey among 1,000 gig workers in February.