They're still legal tender, you can pay things with them. They just stopped producing new ones. It's supposedly permanent, but they can continue producing it any time in the future if they really wanted to.

Well, they still exist and you can still pay for things with them (though a lot of businesses won’t give you them in change, and just round up to the nearest $0.05).

I guess it’ll be a few years before they’re out of circulation entirely.