There are public phones available almost everywhere in Costa Rica.
They can be used to make calls anywhere in the world. These telephones function by using public telephone ICE cards. Buy them in 500, 1000, 5000 colones denominations at many authorized dealers – Universidad VERITAS book store, mini-markets, pharmacies, and liquor stores – that display the blue and yellow ICETEL sign.
Costa Rican phones operate similarly to those in the US. In all of Costa Rica, the area code (lada) is 506 and a number is usually written like this: 2246-4646. If you want to dial this number from the US, first dial “011” + 506 (area code) + number.
If you are bringing your smart phone from home, make sure to contact your phone company to confirm you will not have trouble putting a new SIM card into your phone. For example, iPhones will need to be "unlocked" prior to your arrival in Costa Rica. If you are bringing a non smart phone from home, make sure it is able to have the SIM card changed. If not, cell phones in Costa Rica are fairly inexpensive and can be purchased on campus or at the local malls.