Local and community banks got a 5% bump in usage among adults between ages 18 and 34, according to a report from Accenture cited by Bloomberg. Larger national and regional banks, meanwhile, saw a 16% dip in millennial clients. Credit unions had a 3% increase.

Why are so many young people opting to leave the familiarity of big brand banks? A lot of it comes down to fees, reports Bloomberg. Bigger financial institutions have higher charges for things like withdrawals and overdrafts.

Millennials are more likely than other generations to switch their primary banks, at a pace that’s nearly the double of other age groups, according to Accenture’s annual consumer banking survey. They also like to do research, and most say they look for prices and reviews online before making a decision.

For more on millennials and money, watch this Fortune video: