The aim of this study was to test the effects of tDCS on adult reading and spelling abilities. Experiment 1 examined whether tDCS improved adults' performance on reading and spelling tests. We found no evidence that left temporal tDCS stimulation improved word spelling, word reading accuracy, or word reading fluency compared to sham stimulation. Experiment 2 tested the effect of left-temporal tDCS stimulation on spelling training in adults. There was no evidence for a facilitatory effect of tDCS on spelling training despite its large and significant effects on adults' ability to spell difficult words. These results, paired with previous studies, argue against the use of tDCS as an intervention for poor reading and spelling until we identify a tDCS paradigm that reliably improves reading and spelling skills.