2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/224842Large higher-order corrections enter the Higgs boson sector of the MSSM via Higgs-boson self-energies. Their effects have to be taken into account for the correct treatment of loop-corrected Higgs-boson mass eigenstates as external (on-shell) or internal particles in Feynman diagrams. We review how the loop corrections, including momentum dependence and imaginary contributions, are correctly taken into account for external (on-shell) Higgs boson and how effective couplings can be derived. The proceedures are implemented in the code FeynHiggs 2.5.8 pages, no figures. Two talks given at the LCWS06 March 2006, Bangalore, IndiaHigh Energy Physics - Phenomenologytext