Hadronic light-by-light contributions to muon g-2

Anticipating the experimental improvements of Fermilab E989 and JPARC E34, an improvement of theory uncertainty for the hadronic contributions to the anomalous magnetic moment is needed.

I will review the current status of theory calculations of the hadronic light-by-light contributions to the muon g-2.  I will focus on first-principles methods such as the dispersive and lattice approaches.