The transport properties of molecules and strongly correlated materials can be understood on the basis of impurity problems. Such problems are particularly interesting when the impurity is driven out of equilibrium, for example by coupling to electrodes at different electrochemical potentials. We present a new scheme to solve such impurity problems on the basis of hierarchical quantum master equations. The scheme employs a hybridization expansion of the time evolution operator, including an advanced, systematic truncation scheme. Its time-local formulation allows to describe both fast and slow dynamics such as, e.g., in the presence of magnetic fields or exchange interactions and, finally, nonequilibrium steady states. Here, we present first results of this new scheme for the description of electron transport through nanostructures and strongly correlated materials.