The San Francisco-based bank said the majority of its 12,000 ATMs across the country experienced intermittent outages over several hours.
Bank spokeswoman Richele Messick said the problem was resolved about an hour after the bank became aware of it around 4 p.m. EST Monday.
Customers who incurred the bank's $2.50 fee for using an out-of-network ATM during the outage will be reimbursed, she said. The reimbursements will be automatically credited.
Messick said the outages were the result of "internal system issues," but declined to be more specific.
The outage was first reported in the Minneapolis Star Tribune's website Tuesday.