The 1997 Uniform Building Code slender wall provisions were incorporated into ACI 318-99 to eliminate conflict with the 2000 International Building Code. Although the equations for determining the design moment remained essentially the same, the service level deflection equations were significantly altered, leading to underprediction of deflections compared to test data. Brought about, in part, by a Structural Engineers Association of Southern California Slender Wall Task Group that re-evaluated the original test results, changes to the slender wall design provisions are proposed for ACI 318-08.