Imposing supersymmetry inevitably connects a theories Higgs-, gauge- and Yukawa-sector. Therefore, the discovery of a 125 GeV Higgs boson at the LHC puts tight constraints on parameter spaces of supersymmetric models which need to predict the correct Higgs boson mass. The importance of higher-order corrections in this game cannot be overemphasized: in the minimally supersymmetric SM, loop-corrections are known to be O(40%) of the tree-level Higgs boson mass prediction.
In the first part of the talk I give a short introduction into the field of Higgs mass calculations based on fixed-order as well es resummation techniques. In the second part I discuss recent progress in the two-loop prediction of the Higgs masses in the CP-violating NMSSM. The focus is set on the treatment of infra-red divergences as well as some phenomenological applications.