Thailand has instituted an emergency degree that bans all non-citizens arriving in Thailand from midnight on March 25 through April 30, 2020.
The country already tightened entry requirements requiring arriving passengers to have a medical certificate that they are not infected with coronavirus (COVID-19) and proof that they have a travel insurance with a minimum of $100,000 in coverage.
Here's an excerpt from the Bangkok Post (read more here):Thailand earlier tried various ways to limit entry to the Kingdom:Foreigners will be banned from entering the country under the emergency decree being invoked to combat at the coronavirus pandemic.
The emergency decree comes into effect at midnight on Wednesday, and remains in force through April 30.
The decree bans all foreigners from entry at all entry points - the exceptions being shippers, diplomats, drivers, pilots and others permitted by Prime Minister Prayut Chan-o-cha.
Thailand Introduces New Entry Requirements March 2020 (App Required + Visa-On-Arrival Canceled For Many)
Thailand Immigration Update: De Facto Ban For All Arrivals Who Can't Produce a 72hr Fresh Medical Certificate & $100k Insurance CoverageConclusion
This entry ban is quite theoretical at this point considering all the other travel restrictions in place and lack of air connectivity.
Also, not sure how many were able to get the required certification of not being infected with the coronavirus. The $100,000 in travel health insurance is not that high.