Electrostatic interactions are key determinants in the assembly and organization of ionic micelles. Here, we synthesized sequence-defined polypeptoid block copolymers with discrete chain lengths and single or triple charged residues arranged in distinct patterns. Model-free small-angle neutron scattering analysis of semidilute polymer solutions at pH 9.0 revealed that intermicellar interactions follow screened Coulomb potentials, with strength and range determined by charge placement. Notably, p