From Halopedia, the Halo wiki
LASO Master is an achievement in Halo: The Master Chief Collection. It is worth 50 gamerscore. To unlock this achievement, the player has to complete the LASO playlists for Halo: Combat Evolved Anniversary, Halo 2: Anniversary, Halo 3, and Halo 4. The LASO playlists for Halo 3: ODST and Halo: Reach are not required.