The recent measurement of a_��=\frac{g_��-2}{2} by the E821 Collaboration at Brookhaven deviates from the quoted Standard Model (SM) central value prediction by 2.6��. The difference between SM theory and experiment may be easily accounted for in a variety of particle physics models employing weak scale supersymmetry (SUSY). Other supersymmetric models are distinctly disfavored. We evaluate a_��for various supersymmetric models, including minimal supergravity (mSUGRA), Yukawa unified SO(10) SUSY GUTs, models with inverted mass hierarchies (IMH), models with non-universal gaugino masses, gauge mediated SUSY breaking models (GMSB), anomaly-mediated SUSY breaking models (AMSB) and models with gaugino mediated SUSY breaking (inoMSB). Models with Yukawa coupling unification or multi-TeV first and second generation scalars are disfavored by the a_��measurement.

25 page REVTEX file with 10 PS figures. Minor rewording, typos corrected, references added