The English-speaking website of the Costa Rica Tourism Board provides updated information about the COVID-19 entry requirements:
We would like to thank all our guests who have been travelling with us since 1994 in the most beautiful time of the year - their well-deserved holidays. When developing itineraries for groups and individual travelers, selecting our local service partners and caring about the well-being of our guests, we always focus on the highest possible quality standards. Since the founding of Amadeus Travel, we have been committed to sustainable tourism as the only long-term viable form of tourism, e.g. through our social commitment, visiting and supporting private and state nature reserves as well as the training of our team and experienced, fully licenced tour guides.