Decoupling and the radiatively-corrected MSSM Higgs sector
  In the decoupling limit of a non-minimal Higgs sector, the lightest CP-even Higgs boson (h) is indistinguishable from the Standard Model (SM) Higgs boson. In the two-Higgs-doublet sector of the MSSM, the approach to the decoupling limit (for m_A>>m_Z) persists, even in the presence of potentially large (tan(beta)-enhanced) radiative corrections to the hbb coupling. Radiative corrections can also generate an accidental cancellation between tree-level and one-loop terms, resulting in a SM-like Higgs boson for moderate m_A outside the decoupling regime. 
Howard E. Haber