This is the info direct from the U.S. Embassy, and please note the "Health Pass" at the end:

Visitors traveling to Costa Rica will need to provide proof of a medical insurance policy to cover any COVID-19 related medical treatment or quarantine lodging while in Costa Rica. In the case of international insurance, tourists must request from their insurer a certification issued in English or Spanish, noting: 1) the validity of the policy during the dates of visit to Costa Rica, 2) guarantee of coverage for medicals expenses in cases of COVID-19 related medical treatment in the amount of 50,000 USD and, 3) minimum coverage of 2,000 USD for extended lodging expenses due to COVID-19 related illness. It is also possible to purchase a Costa Rican medical insurance policy through the National Insurance Institute (INS) or Sagicor of Costa Rica, covering the duration of your stay in Costa Rica. Please send an email to seguros@ict.go.cr for questions about insurance coverage or to verify your current insurance policy will be accepted in Costa Rica.

Costa Rican Immigration officials have sole authority to determine the length of stay for tourists entering Costa Rica. Immigration officials are currently limiting the duration of stay to correspond with coverage dates provided by the COVID-19 medical insurance. Tourist seeking to extend their stay beyond the date indicated by immigration officials must contact the Migracion Call Center at 1311. Tourists are not able to extend their stay in Costa Rica beyond 90 days.

All visitors must also complete an online Health Pass (pasa de Salud) 48 hours prior to travel to Costa Rica. The Health Pass can be found at https://salud.go.cr.

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