Aeropuerto Internacional Juan Santamaría (San José) Buses (about US$1.50) from the airport to central San José run hourly all day. Taxis charge from US$30 and depart from the official stand; the trip takes 20 minutes to an hour. Interbus runs between the airport and San José accommodations (US$17 per adult, children under 2 free if sharing a seat). Many rental-car agencies have desks at the airport, but it's advisable to book ahead.
Aeropuerto Internacional Daniel Oduber Quirós (Liberia) Buses run to the Mercado Municipal (around US$1, 30 minutes, hourly) between 5am and 9pm Monday to Saturday, less frequently on Sunday. Taxis between the airport and Liberia are about US$20. There are no car-rental desks; make reservations in advance and your company will meet you at the airport with a car.