If I have one or more connecting flights to the US, does the 3-day period apply to the first flight or the last one? Do I need to get another test if I have a connecting flight?
If your itinerary has you arriving to the US via one or more connecting flights, your test can be taken within the 3 days before the departure of the first flight.
If the 3-day testing period expires before one of your connecting flights, you only need to get retested before boarding connecting flights if:
- You planned an itinerary incorporating one or more overnight stays en route to the US. (NOTE: You do not need to be retested if the itinerary requires an overnight connection because of limitations in flight availability.), OR
- The connecting flight is delayed past the 3-day limit of testing due to a situation outside of your control (e.g., delays because of severe weather or aircraft mechanical problem), and that delay is more than 48 hours past the 3-day limit for testing.
How does the CDC define more precisely the following condition:
if the itinerary requires an overnight connection because of limitations in flight availability.
E.g. in the case of my friend flying to the US, his flight has a layover of around 8 hours from very early AM (quite close to midnight) to the beginning of the morning: the layover is inevitable if flying with his preferred airline and departing at a specific day. However, if he decides to flight the next day with the same airline, then the layover is just around 3 hours. In that context, does the CDC think that his itinerary requires the 8h layover? (I don't intend to discuss whether this 8h layover is overnight: see How does the CDC define an overnight stay? for that question. Let's just assume it is.)