Abstract Kleptoplasty is a mixotrophic condition acquired by a heterotrophic grazer that ingests photosynthetic eukaryotic cells, wherein the plastids are not digested but rather are retained in the heterotrophic cell or organism in a photosynthetically active state. This phenomenon has been described in select foraminiferal taxa inhabiting nearshore and salt-marsh coastal habitats. We applied molecular and microscopic techniques to living foraminifera collected from South Carolina salt marshes (Waties Island and North Inlet) to determine if we could detect kleptoplasty. Sequence and confocal-imaging data recovered from 2 foraminiferal genera (Elphidium and Haynesina) indicated the functional retention of diatom plastids within these taxa.