Roma Pass and Borghese gallery

You need to call. Here is the info:

ROME PASS AND ROME & MORE PASS
The Galleria Borghese is part of the Roma Pass and Roma

& Più Pass circuits . Ticket reservations are mandatory.
Customers in possession of the Roma Pass are invited to make the
reservation only for the entrance by calling +39 06 32810

I just called for a disabled reservation which is the only way to do it for the disabled and a companion since it is free. The information on the phone was in Italian and then English. The person that answered spoke English. I received a reservation number for the day and time I requested.

I just checked the website where we bought our tickets a couple of years ago, and found this:

Ticket reservations are required for all visitors. Visitors who plan
to use a Roma Pass ... cannot book online they must book
by phone calling +39 06 32810 and picked up at the ticket office of
the museum 30 minutes before the time choosen, showing the booking
confirmation with the Roma Pass Card.

The part I elided has to do with tour guides, who also cannot book online.

Any idea how far in advance to call for the Borghese date and time reservation before the actual date of arrival. This will be near Easter.

Check the website to see how far in advance they release tickets. Just do a test like 90 days from now to see if you theoretically could do it. Once you can make an online res, you can also do it by phone.

By the way, if you decided to use their tour, you can't use your Roma Pass for it. You have to book your tour either by calling them or on their website.

Also, if you saw they have refunded from your credit card statement about a month prior to your visit, that means your reservation is cancelled. You can save yourself a trip to the Gallery