Automatic teller machines hold a limited amount of cash, so banks limit the amount of cash you can withdraw. The exact limits for withdrawing cash from an ATM vary from one institution to another and depend on the type of account that you have. Be sure to check with your bank to find out what kind of limits it places on ATM withdrawals.
Federal regulations limit you to six monthly withdrawals from money market accounts or savings accounts, including withdrawals made at ATMs. For checking accounts, the limits are set by the banks themselves and may depend on the type of account you have. Banks may limit the size of each withdrawal and the number of times you can make withdrawals in a set time, such as per day.