This paper presents research into the relative frequencies of phonemes in Romanian, focusing on the high central vowel /ɨ/ to demonstrate how type frequency reflects its former allophonic status as an allophone of /a/ and later /ə/; and that the low type frequency of /ɨ/ correlates with the vowel’s minimal expansion beyond its original allophonic environments. The historical facts show that [ɨ] was allophonic in native words of Latin origin, emerging mainly through pre-nasal raising. Borrowings from Slavic, however, cannot be explained through allophony alone, and later borrowings from Turkish show a correspondence between Turkish [ɨ] and Romanian /ɨ/, indicating the vowel was on the verge of phonemic status. Although /ɨ/ is synchronically contrastive in Romanian, its contrastiveness is marginal; few minimal pairs separate the once-allophonic /ɨ/ and /ə/. A type-frequency analysis allows us to examine the functional load of phonemes in modern Romanian, for comparison with the historical picture. Among the vowels of Romanian, type frequency varies widely; the least-frequent vowels are /ɨ/ and /ə/. The low type frequency of /ɨ/ in particular follows from its origins as an allophone, and from the circumstances of its phonemicization: /ɨ/ was originally conditioned in stressed syllables preceding a nasal, and also by a preceding /r/ or following /rC/. This is precisely the variety of phonological conditioning that can be shown through this type-frequency analysis. With regard to /ɨ/, I argue that in the vowel’s type frequency, we see little more than the phonological footprint of the processes that brought /ɨ/ into Romanian: the role of /ɨ/ has not expanded much beyond its original allophonic role.