Changing service info

I have a phone through my food stamps. I've had it for approximately 3 years... I am with SafeLink I'm wondering if I can change over to att.  is that possible? Do they participate in this program I don't pay anything for my phone service at all, unless I need extra data...and I get so much data so many text messages and so many talk minutes per month. I would also like to know about the hot spot device is that covered?