We investigated how grapheme familiarity and grapheme-phoneme correspondence (GPC) congruence affect adult learners' ability to make use of orthographic input (OI) during phono-lexical acquisition. Native English speakers, with no Russian experience (naïve) or learners of Russian, heard auditory forms, saw pictured meanings, and saw written input either in a No Orthography condition or an Orthography condition for words that contained unfamiliar Cyrillic graphemes, familiar graphemes and congruent GPCs, and familiar graphemes and incongruent GPCs. Naïve participants evidenced incongruent GPC interference effects. Experienced learners acquired targetlike GPCs, although beginner learners did not. In a separate experiment, naïve learners were exposed to an intervention to mitigate effects of OI; the interventions did not improve test accuracy. Results support previous findings that incongruent GPCs interfere with phono-lexical acquisition. We also found evidence that target language experience mitigates negative effects of OI, but interventions may not sufficiently aid naïve learners' phono-lexical acquisition.