Switch from Verizon to At&t. 2 year contract expired in April 2016. Phone has been disconnected since December of 2015. Bill in collections for termination fees and last month's bill. Can I activate this phone with another carrier?
No you can't. The phone is locked until you pay that bill and they won't give you a release code to pass on to another service provider. Even if you bought another phone, your name might be blacklisted so it's better all round to find the money and pay that bll.
Losing a good credit rating is a serious matter because it can stay with you for years.