Tocumen International Airport has announced that, following the opening of the airport for international travel, all passengers, wether they be, residents, nationals or internationals, must present a a negative PCR test for COVID-19 taken 48 hours before entering the country. If you were unable to get a PCR test done, the airport has the option of getting the PCR test done in the airport before passing through migration. The test costs 50 USD and takes approximately 20-30 minutes.
If your test is negative, either when taken previous to traveling or at the airport, there will not be any need to quarantine once you have entered the country.
Safe travels!