Annealing of dry, short side chain Na+-perfluorosulfonate ionomers at a submelting temperature above the ionic cluster glass transition results in increased order and more structural cohesion in the matrix and disruption of order in the clusters as seen by DSC. Hydrative capacity increases with increased annealing. Electrical impedance studies show how the permittivity representation of data is most useful for studying long-range ion motions while admittance is better suited for detecting cluster-confined motions. A cluster-associated peak was rationalized as shifting to lower frequencies with increase in temperature/time of annealing due to an increase in hydrated cluster size. Analysis of the distribution of relaxation times indicates that annealing above the cluster glass transition induces considerable microstructural regularity within these membranes. Permittivity/admittance spectra of "dry" and hydrated membranes suggest that annealing induces ion-hopping pathways that are rather tortuous. It is proposed that, while side chain packing within clusters becomes disordered upon annealing, the semicrystalline matrix surrounding clusters becomes more homogeneous and tightly packed, thereby blocking intercluster ion hopping to a greater degree.