The recently reported measurement of the muon's anomalous magnetic moment d
iffers from the standard model prediction by 2.6 sigma. We examine the impl
ications of this discrepancy for supersymmetry. Deviations of the reported
magnitude are generic in supersymmetric theories. Based on the new result,
we derive model-independent upper bounds on the masses of observable supers
ymmetric particles. We also examine several model frameworks. The sign of t
he reported deviation is as predicted in many simple models, but disfavors
anomaly-mediated supersymmetry breaking.