Will I be required to pay a departure tax?

Yes, everyone departing from LIR or SJO must pay the $ 29 USD departure tax, though most airlines now include it in the price of the ticket (please check with your airline).  This must be paid before airline check-in for your departure flight.  There is a departure tax counter at each airport.  You can pay with colones, U.S. dollars, or with a Visa credit or debit card.  If paying with a credit or debit card, an additional fee ($10) will be charged as it will be processed as a cash advance.  Under normal circumstances, the process is quick and easy, usually taking less than 10 minutes.  Some (not all) airport hotels will process this for you for an additional fee.