reservation for Narita Express with JR Pass

Hi! Maybe the title of my question is unclear so let me add some details.
I'm arriving to Narita at 17:30. I have a JR pass voucher which i have to exchange to JR Pass Ticket. From Narita I need to get to Shinjuku. I tried Hyperdia and it seems that the best option is to take Narita Express. But there's a notice that Narita Express can only be used with a seat reservation (If I understood it right). So the question is can I make a seat reservation while exchanging my voucher for Narita Express which departs at ~21:00 same day?

Yes.

Thank you, AK!

you can reserve a seat when you exchange your JR pass, if you're arriving at 17:30 then you'll probably be catching a train into tokyo for around 7pm.

Unless you're travelling onto somewhere else other than tokyo it would probably be a waste of a day to exchange your pass that evening, unless your pre dating it.

Yes, I have 14-days JR Pass and all these days including the day of my arrival are covered. I was only concerned because I thougnt that seat reservations should be done earlier than couple hours before departure.

Narita Airport isn't that busy an airport. Granted most international flights arrive there, there are multiple options for getting into Tokyo from Narita airport. There are two rail lines: one from JR (N'Ex) and the other from Keisei. The Keisei tends to be cheaper. There's also a limousine bus service that carries people to many hotels.

By the number of options and arrivals, there's no way any one train will be so full you won't be able to board it, especially the JR line. Those trains are long and can carry quite a few passengers. I've taken them nearly a dozen times and not once did I even have to sit next to anyone around me. Most times the car was a quarter full at most for an arrival time of 2pm-3pm....