  We report a lattice QCD calculation of the hadronic light-by-light
contribution to the muon anomalous magnetic moment at physical pion mass. The
calculation includes the connected diagrams and the leading,
quark-line-disconnected diagrams. We incorporate algorithmic improvements
developed in our previous work. The calculation was performed on the $48^3
\times 96$ ensemble generated with a physical-pion-mass and a 5.5 fm spatial
extent by the RBC and UKQCD collaborations using the chiral, domain wall
fermion (DWF) formulation. We find $a_\mu^{\text{HLbL}} = 5.35 (1.35) \times
10^{- 10}$, where the error is statistical only. The finite-volume and finite
lattice-spacing errors could be quite large and are the subject of on-going
research. The omitted disconnected graphs, while expected to give a correction
of order 10\%, also need to be computed.
