You have to make a personal visit to the MTA office in the Wall St area and apply. They check id and take a photo. There will be a wait before they call you.

There is no charge. It will show up in the mail sometime later if you want it to go to your credit card, but they give you something right then as I recall.

It works exactly like a regular photo MTA card but everything is half price.

You don't have to be a resident or anything, I used my California DL as ID and the statement comes to my home.