Previous research has shown the importance of sublexical orthographic cues in determining the language of a given word when the two languages of a bilingual reader share the same script. In this study, we explored the extent to which cross-language sublexical characteristics of words—measured in terms of bigram frequencies—constrain selective language activation during reading. In Experiment 1, we investigated the impact of language-nonspecific and language-specific orthography in letter detection using the Reicher–Wheeler paradigm in a seemingly monolingual experimental context. In Experiment 2, we used the masked translation priming paradigm in order to better characterize the role of sublexical language cues during lexical access in bilinguals. Results show that bilinguals are highly sensitive to statistical orthographic regularities of their languages and that the absence of such cues promotes language-nonspecific lexical access, whereas their presence partially reduces parallel language activation. We conclude that language coactivation in bilinguals is highly modulated by sublexical processing and that orthographic regularities of the two languages of a bilingual are a determining factor in lexical access.