The N400 event-related potential (ERP), a marker of lexical-semantic processing, can assess the neural basis of reading difficulties. This study examines 1) semantic processes in typically developing (TD) children and children with reading disabilities (RD) using N400 and Set-for-Variability (SfV) profiles and 2) correlations between N400 and SfV. Fifty-one children read congruent and incongruent sentences during EEG. Results showed RD children lacked an N400 effect and had delayed SfV. A negative correlation between SfV and N400 latency in the RD group indicated distinct semantic processing delays in these children.