  Dirac-Schr\"{o}dinger systems play a central role when modeling Dirac bundles
and Dirac-Schr\"{o}dinger operators near the boundary, along ends or near other
singularities of Riemannian manifolds. In this article we develop the Fredholm
theory of Dirac-Schr\"{o}dinger systems with Lipschitz coefficients.
