Hey there, cgoldmann! This is the list of devices we are able to activate coming from other companies https://www.boostmobile.com/#!/bring-your-phone/ From Sprint this is the list https://www.boostmobile.com/#!/support/faq/phones-devices/activate-a-sprint-phone/
For the moment our BYOD program, includes the listed models from T-Mobile, AT&T, Verizon, and their MVNO's respectively, unless specified. You can use our IMEI check tool online to verify your phone's eligibility. We hope this information helps. -Edwin R.