Abstract : Consider initial problems for nonlinear singularly perturbed systems of the form epsilon sub z dot = f(z,t,epsilon) in the singular situation that f sub z(z,t,0) has a nontrivial null space. Under appropriate hypotheses, such problems have asymptotic solutions as epsilon approaches 0 for t or = 0 consisting of the sum of a function of t and a function of tau = t/epsilon. These problems arise in a number of situations in fluid dynamics and optimal control.