FCO-JFK-SFO Flight

You go through passport control and have to retrieve your checked baggage at JFK. That sounds like the perfect amount of time as long as the first flight leaves on time.

I would think, barring extraordinary circumstances, that you should have ample time. The airlines would not be scheduling high risk connections as they would have to always be making special arrangements for a plane load of passengers.

Hopefully people who use JFK frequently will opine on the time it takes. You will have to clear passport control and customs (that's why you have to retrieve your bags) in JFK. (Usually? always?) the airline has a service right after customs to take your luggage so you don't have to schlep it around and wait in line to check bags. You will still have to go through a security check before your next flight.

At JFK, you'll clear passport control, pick up your bags, clear customs, re-check your bags (which will just involve dropping them on a belt right after customs) and then re-clear security.

The only possible minor wrinkle is that Delta operates out of two terminals at JFK, terminals 2 and 4. Your FCO-JFK flight will definitely arrive in terminal 4, and the majority of Delta's SFO-JFK flights also operate out of terminal 4, but there are a couple of oddball SFO-JFK flights that operate out of terminal 2. (For example today there are 7 of these flights; the last one of the day operates out of T2 and all the other ones out of T4).

There is a landside (pre-security) AirTrain between T2 and T4, and Delta operates an airside (post-security) shuttle between T2 and T4, so the transfer is not difficult to make. I'd just look to see if your JFK-SFO flight is operating right now and see what terminal it's operating out of -- if it's out of T4 now, it is likely (though not certain) it will also operate out of T4 for your ticket.

Andrewesque is correct......Delta operates an air-side shuttle between terminals 2 and 4 so you should not have to exit and go back through security - assuming your FCO-JFK flight is on Delta metal. If you are on a code-share you might have to - this happened to us a year or so ago when we were on a Delta ticket but on Air France metal from CDG and actually arrived in Terminal 1..

Hi herronlaw -- the OP will have to re-clear security no matter what, even with the airside shuttle, because you always have to re-clear security when you do an international-to-domestic transfer at a US airport (unless you are arriving from an airport with preclearance like the major Canadian ones or Dublin).

It's because you always have to go through customs at your first point of entry to the US, which means you have to pick up your checked bags; and if you've had access to your (or any) checked bags, you have to get re-screened by security as you may have then had access to things that are prohibited after security but allowed in your checked bags (like knives).

That being said, in major airports there's usually a dedicated re-screening checkpoint that is separate from and often faster than the checkpoint for originating passengers at that airport. But you can't avoid the re-security screening completely.

Good point. We had to do that in Terminal 1 last year upon arrival. As I recall we initially went through that security screening in Terminal 1. We had to re-do it again for a second to get into Terminal 4 for our connecting Delta flight.

That should be enough time to clear everything, grab your bags, go through security again, etc. at JFK, but to increase your chances, go ahead and download the Mobile Pass app on your phone. It can significantly speed up your progress.

One further wrinkle is that your "Delta" flight from FCO to JFK may be on Delta metal (arriving in Terminal 4) or Alitalia metal with a Delta flight number (arriving in Terminal 1). To get from Terminal 1 to Terminal 4, take the Airtrain going to either Howard Beach or Jamaica; do not take the other Airtrain going the other way, as it will take much longer (yes, there are three Airtrain routes, going in two directions!).

Since you have to re-clear security anyway, it will not add too much time if you have to change terminals, but it will add some, compared with just going upstairs from your T4 arrival to your T4 departure.

Arriving at JFK, if you do not have Global Entry, be sure to use the Mobile Passport App! Particularly at the Delta terminal, lots of overseas flights arrive around the same time, and regular passport control lines can be a mob scene.

You could also look at a flight that connects in Amsterdam or Paris, so that your US point of entry would be SFO.