  Isospin-breaking corrections to the hadron vacuum polarization component of
the anomalous magnetic moment of the muon are needed to ensure the theoretical
precision of $g_\mu -2$ is below the experimental precision. We describe the
status of our work calculating, using lattice QCD, the QED correction to the
light and strange connected hadronic vacuum polarization in a Dashen scheme. We
report results using physical $N_f=2+1+1$ HISQ ensembles at three lattice
spacings and three heavier-than-light valence quark masses.
