U. S. checks are accepted in a few places in Costa Rica. Some banks will hold your check for up to 45 days before it clears. You can use ATMs connected to US accounts to get both US dollars and Costa Rican colones. You will need enough cash to sustain you until you can establish a local account or until you learn to use the ATMs here. Some ATMs charge approximately $2.00 per transaction, others charge a percentage, but you get a better exchange rate which offsets some of the charges.
Credit cards are accepted almost everywhere and you may choose to use them rather than cash. VISA and MasterCard are the most common, although if there is a problem using an ATM, it can be difficult to find a bank that will deal with MasterCard. VISA cards are best. (Discover Card is not recognized in Costa Rica.) Some credit cards charge up to a 3% fee for every foreign transaction made, although it may be possible to have the charge waived. Check with your bank regarding the number of transactions you are allowed with your debit card at a foreign ATM, and let them know you are moving to Costa Rica. This will avoid a hold being placed on your card for fraudulent purchases. Your Big Brother/Sister will show you how it all works when you arrive.