Transport coefficients are derived which govern the current response of phase coherent conductors in the presence of slowly oscillating external perturbations. We derive the low-frequency admittance if oscillating voltages are applied to the contacts of the sample and discuss the response to an oscillating magnetic flux. Whereas the dc-conductance is determined only by the equilibrium electrostatic potential, the adiabatic transport coefficients discussed here depend on the electrostatic potential that is established in the presence of transport. The symmetry of the transport coefficients under flux reversal is discussed. Novel experiments to find Aharonov-Bohm oscillations in capacitance coeffcients are suggested.