  Recent evidence for an excess of gamma rays in the GeV energy range about the
Galactic Center have refocused attention on models of dark matter in the low
mass regime ($m_\chi \lesssim m_Z/2$). Because this is an experimentally
well-trod energy range, it can be a challenge to develop simple models that
explain this excess, consistent with other experimental constraints. We
reconsider models where the dark matter couples to dark photon, which has a
weak kinetic mixing to the Standard Model photon, or scalars with a weak mixing
with the Higgs boson. We focus on the light ($\lesssim 1.5 GeV$) dark mediator
mass regime. Annihilations into the dark mediators can produce observable gamma
rays through decays to $\pi^0$, through radiative processes when decaying to
charged particles ($e^+e^-, \mu^+\mu^-,...$), and subsequent interactions of
high energy $e^+e^-$ with gas and light. However, these models have no signals
of $\bar p$ production, which is kinematically forbidden. We find that in these
models, the shape of resulting gamma-ray spectrum can provide a good fit to the
excess at Galactic Center. We discuss further constraints from AMS-02, and find
regions of compatibility.
