What if supersymmetry breaking unifies beyond the GUT scale?

We study models in which soft supersymmetry-breaking parameters of the MSSM become universal at some unification scale, M_in, above the GUT scale, M_GUT. We assume that the scalar masses and gaugino masses have common values, m₀ and m_1/2 respectively, at M_in. We use the renormalisation-group equations of the minimal supersymmetric SU(5) GUT to evaluate their evolutions down to M_GUT, studying their dependences on the unknown parameters of the SU(5) superpotential. After displaying some generic examples of the evolutions of the soft supersymmetry-breaking parameters, we discuss the effects on physical sparticle masses in some specific examples. We note, for example, that near-degeneracy between the lightest neutralino and the lighter stau is progressively disfavoured as M_in increases. This has the consequence, as we show in (m_1/2,m₀) planes for several different values of tan β, that the stau-coannihilation region shrinks as M_in increases, and we delineate the regions of the (M_in,tan β) plane where it is absent altogether. Moreover, as M_in increases, the focus-point region recedes to larger values of m₀ for any fixed tan β and m_1/2. We conclude that the regions of the (m_1/2,m₀) plane that are commonly favoured in phenomenological analyses tend to disappear at large M_in.