Systems, devices and methods for adaptive switching in multicast media streams are disclosed herein. In an embodiment, a method for adaptively transmitting content to one or more users based on currently available bandwidth via internet protocol (“IP”) multicast protocol, includes: receiving a first content stream having a plurality of data packets, the first content stream encoded at a first bit rate; receiving a second content stream having a plurality of data packets, the second content stream encoded at a second bit rate, wherein the first bit rate is different than the second bit rate and wherein the first and second content streams represent the same content; transmitting the first content stream to a user; determining that the user could receive the second content stream based on available bandwidth for transmitting data to the user; and transmitting the second content stream to the user.