"A Decade Underground" is the final album of the collection and only available for download for those who have the LPUX Annual Pass. This collection includes songs released over the ten years of the LPU and never before released demo.
■ "And One" and "Part of Me" can be heard on the Hybrid Theory EP in 1999 and on the reissue for the LP Underground 1.0 in 2001. They both originally appeared on the Songs from the Underground extended play in 2008.
■ "Dedicated (Demo 1999)" can be heard on LP Underground 2.0. It can also be heard on Songs from the Underground.
■ "Sold My Soul To Yo Mama" can be heard on LP Underground 4.0, containing samples of "Points of Authority" and "Papercut" that originally appeared in their first studio release, Hybrid Theory. The song originally appeared on Songs from the Underground.
■ "Announcement Service Public" and "Qwerty" can be heard on LP Underground 6.0. Both tracks originally appeared on Songs from the Underground.
■ The piano version of "My December" in 2008, and the Temple Of The Dog cover of "Hunger Strike" performed by Chris Cornell with the band's frontman Chester Bennington, can now be heard on the band's second extended play, Songs from the Underground.
■ "Across The Line (2007 Demo)" can be heard on LP Underground 9.0: Demos.
■ "Pretend To Be (2008 Demo)" can be heard on the LP Underground X: Demos EP that launched in 2010.