If you plan to submit your music to HD or Ultra HD streaming services such as Amazon HD, Deezer, or Tidal then you will need to embed files in the lossless FLAC format.
For example, at last check, Amazon HD streams using FLAC in 16 bit, 44.1 kHz, up to 850 kbps and Amazon Ultra HD streams using FLAC in 24 bit, 192 kHz, up to 3730 kbps.
We recommend that you embed in the standard-definition (SD) format (MP3, for example) your standard streaming services require AND embed separately in FLAC for HD and/or UHD streaming.