The frequency response of a model mechanism for acceptor-limited electrochemical polishing is investigated. The mechanism consists of charge-transfer and surface-reaction steps involving adsorbed intermediates in the absence of precipitate films with electropolishing resulting from mass-transport limitations for a solvating acceptor species arriving at the surface from the bulk electrolyte. Important qualitative differences in the impedance diagrams between the acceptor mechanism and the more commonly observed salt-film precipitation mechanisms permit a clear distinction to be made concerning the likely origin of the polishing phenomenon in a given experimental system. Whereas in salt-film mechanisms the position and size of the high-frequency loop in the impedance diagrams can depend strongly on convection and applied potential, for the acceptor mechanism the high-frequency limit is unaffected by potential and convection, and the diameter of the first impedance loop is independent of potential along the limiting current plateau. At low frequencies as well the two models differ considerably. In particular, systems operating under an acceptor-limited mechanism can exhibit features influenced by Warburg-Nernst impedances, while salt-film systems cannot. A comparison of the shapes of the impedance diagrams and the characteristic behavior of the high-frequency loops with recent experimental measurements for the anodic dissolution of iron-chromium alloys in phosphoric and sulfuric acid supports the hypothesis that the iron-chromium system is governed by acceptor transport in the limiting-current region.