You need to fill out New York health form online. When completed, you'll get a green check mark on your completed form indicating you have. There are national guardsmen before you exit the arrival lounge to check. If you don't have it, they make you complete a paper form. To the best of my knowledge, they just look at the green check mark. I don't know what check mark you get off you have a negative result and what they do.
No proof needed. But the national guard was there to make sure that you fill out the documents
No you just have to fill out a paper as soon as you get off the plane at Laguardia.
For internal flights the test is not necessary at this time.
I recently went to NY from Panama City Fl and Delta's website said I needed to show proof of a negative test. But when I got to the airport in NY all they did was make me fill out a form and let me leave. I didnt even have to get tested to come back.
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