Shakur died Sept. 13, 1996, of gunshot wounds he sustained in an as-yet-unsolved drive-by shooting in Las Vegas. He was 25.
Had he lived, he would have celebrated his 40th birthday last month. Universal said the albums are being released on iTunes to mark the milestone.
The albums made available this week digitally are "2Pacalypse Now," "Strictly For My N.I.G.G.A.Z.," "Thug Life -- Volume 1," "Me Against the World" and "R U Still Down?"
The record label noted Shakur is the best-selling rap/hip-hop artist in history, with more than 75 million albums sold worldwide.