Most banks offer exchange currency at any local branch, however, most do not have foreign currency on hand. To be safe, order foreign currency two weeks in advance to allow time for delivery. Many banks, such as Bank of America, also provide online foreign currency ordering services, as of 2015.
Banks generally offer good foreign exchange rates with low fees, and most only take a few days to deliver foreign currency. Avoid going into your local branch unnecessarily by ordering currency online. Search for "foreign currency" or "currency exchange" on your bank's website to find currency exchange information. Some major bank branches in major cities may have foreign currencies on hand, which is useful if you live in those areas and are pressed for time. Phone first to make sure they have the currency you desire.
Other currency exchange businesses also run stores in many cities and offer online ordering services. These businesses generally charge higher fees than banks, but may also offer more immediate service.
Many banks offer accounts with ATM cards that customers can use at foreign ATMs with fees comparable to exchanging money at home. Some travel-centric credit cards also offer very low fees when used in foreign countries, and some credit cards charge no extra foreign fees at all.