On April 23, 2017, Technicolor’s mp3 licensing program for certain mp3 related patents and software of Technicolor and Fraunhofer IIS has been terminated.
We thank all of our licensees for their great support in making mp3 the defacto audio codec in the world, during the past two decades.
Source: Fraunhofer IIS - mp3
I’m not sure what this means in situations that used to require license fees. Licensing MP3 has been an issue in open source products like Ubuntu and Firefox in the past, and a reason that many games and some streaming services use Ogg Vorbis instead. (Spotify used to use Ogg Vorbis, not sure about now, however.)