The present study tested whether listeners hearing one form of a morpheme activate other forms of the same morpheme. Listeners performed lexical decisions while hearing Mandarin monosyllables; crucially, critical targets could be primed by related syllables that occurred 18–52 trials earlier (long-lag priming). The use of long-lag priming ensures that any facilitation effects are due to morphological relatedness and not to semantic or form relationships, which do not prime lexical decisions at long lags. Across three experiments (total N = 458), we consistently found that lexical decisions were primed when the same pronunciation of a morpheme occurred as prime and target (e.g., shiL – shiL) but were not primed when two different variants of the same morpheme occurred as prime and target (e.g., shiR – shiL, where both of these syllables are potential pronunciations of the same morpheme). In other words, we observed identity priming but not morphological priming, unlike other long-lag priming experiments, which almost invariably observe intramodal morphological priming if they test it. This surprising finding suggests that there are boundary conditions on the elicitation of long-lag morphological priming effects.