  We study the presence of impurity bound states within a five-band Hubbard
model relevant to iron-based superconductors. In agreement with earlier
studies, we find that in the absence of Coulomb correlations there exists a
range of repulsive impurity potentials where in-gap states are generated. In
the presence of weak correlations, these states are generally pushed to the
edges of the gap, whereas for larger correlations the onsite impurity potential
induces a local magnetic region which reintroduces the low-energy bound states
into the gap.
