  We discuss the recent results on the muon anomalous magnetic moment in the
context of new physics models with light scalars. We propose a model in which
the one-loop contributions to g-2 of a scalar and a pseudoscalar naturally
cancel in the massless limit due to the symmetry structure of the model. This
model allows to interpolate between two possible interpretations. In the first
interpretation, the results provide a strong evidence of the existence of new
physics, dominated by the positive contribution of a CP-even scalar. In the
second one, supported by the recent lattice result, the data provides a strong
upper bound on new physics, specifically in the case of (negative) pseudoscalar
contributions. We emphasize that tree-level signatures of the new degrees of
freedom of the model are enhanced relative to conventional explanations of the
discrepancy. As a result, this model can be tested in the near future with
accelerator-based experiments and possibly also at the precision frontier.
