GAIT (an acronym for the GSM-ANSI-136 Interoperability Team) is a wireless standard developed in 1999 that allows cross-operation of mobile telephone technologies. Phones compliant with the GAIT standard can operate on either contemporary GSM networks, or the legacy IS-136 TDMA and AMPS networks found extensively throughout North America.

Since GAIT phones are interoperable over several types of networks, users could operate their phones in a much larger area of North America compared to phones that used only the GSM standard. The modern equivalent of a GAIT phone would be a GSM phone that also supports the CDMA IS-95 modes used in North America. Such phones are sometimes called "world phones," although this phrase is also used to describe a GSM phone that supports all four frequency bands used throughout the world.