The best way for students to stay in euros while in Spain (or elsewhere in Europe) is by using their American debit cards to draw cash from the many ATMs (cajeros automáticos) in Spain. The ATM will issue euros (1 euro = $1.3 roughly in 2014, but check for the most current exchange rate), although your account at home is denominated in dollars. ATMs fees vary from bank to bank, but the typical charge is $3 to $5 per transaction or a percentage-defined commission for each withdrawal. Shop around at home for a bank that offers the most favorable currency conversion rate and commissions.
Students are strongly advised to bring two American debit cards and carry only one at a time (leave the other one safely at home at the orientation site or in Madrid). ATMs can, occasionally, eat an ATM card (it happens rarely but always at the worst possible times), which is why you should take a back-up. Before departing for Spain, call your ATM and credit-card companies and let them know the dates you will be in Spain. If you do not notify them in advance of your arrival in Spain THEY WILL ALMOST CERTAINLY BLOCK your use of the cards while abroad.
If you have dollars on you when you arrive at the airport and want to convert them to euros, your best bet is the American Express offices in the big international airports. But in general, avoid exchanging dollars in small amounts–it can be quite expensive and make you lose too much money in the exchange.
The Program will disburse money to students at the beginning of every month so they can cover one meal a day (11 euros a day), their monthly transportation card, as well as the reimbursement of cultural activities (Guidelines for reimbursement of cultural activities).
Students staying for the entire academic year are advised to open a bank account at a Spanish bank–more information on this will be available once you arrive in Madrid.