  The lightest CP-even Higgs boson $h$ in the minimum supersymmetric standard
model (MSSM) has a mass upper bound depending on the top quark and squark
masses. An $e^+e^-$ collider with enough energy and luminosity to produce $h+Z$
at measurable rates up to the maximum $h$ mass would cover the entire MSSM
parameter space, if $h+A$ production was also searched for. We explore the
energy and/or luminosity needed for various top quark and squark masses. For
$m_t=150$\,GeV and 1\,TeV SUSY mass scale, a 230\,GeV collider with
10\,fb$^{-1}$ luminosity would suffice.
