No. Although Boost uses SIM cards like AT&T. They are not even remotely compatible. Boost uses iDEN network technology and AT&T uses GSM-based network technology. Two completely unrelated and incompatible technologies. AT&T phones (unlocked) can be used with T-Mobile and other GSM carriers. Boost phones can only be used (unlocked) with other iDEN carriers like (parent) Nextel. CDMA network technology is used by Verizon, Sprint, USCellular, old Alltel, MetroPCS, and Cricket, to name a few. This network technology is also incompatible with GSM and iDEN. SIM cards are not used by CDMA providers.