The authors examined patterns of facilitation under forward-masked priming conditions across 3 list contexts (Experiments 1-3) that varied with respect to properties of filler trials--(a) mixed (morphological, orthographic, semantic), (b) identity, and (c) semantic--but held the relatedness proportion constant (75%). Facilitation for targets that were related morphologically to their prime occurred regardless of filler context, but facilitation for semantically related pairs occurred only in the context of identity and semantic fillers. Facilitation was absent for orthographically similar prime-target pairs in all 3 filler contexts when matching numbers of orthographically similar word-word and word-nonword prime-target pairs rendered orthographic similarity uninformative with respect to lexicality of the target. Enhanced semantic and morphological facilitation in the context of identity and semantic relative to mixed fillers support a semantically attuned, as contrasted with a purely form-based, account of early morphological processing. (Contains 3 tables and 2 footnotes.)