The discrepancy between the Standard Model (SM) prediction for the anomalous magnetic moment of the muon g-2 and the experimental measurement at Brookhaven has received a lot of attention during the past decade. On April 7th, we expect to see highly anticipated first results from the FNAL g-2 experiment. The status of the SM prediction has recently been summarized in a white paper of the g-2 theory initiative. In my talk, I will give a brief overview and discuss in more detail hadronic contributions that are responsible for the bulk of the SM uncertainty. I will explain the dispersive frameworks for hadronic vacuum polarization (HVP) and hadronic light-by-light scattering and I will comment on recent developments regarding the HVP contribution, where cross-section measurements are challenged by improved lattice-QCD determinations.