The phonetic context in which word-medial flaps occur (in contrast to [t[superscript h]]) in American English is explored. The analysis focuses on stress placement, following phone, and syllabification. In Experiment 1, subjects provided their preference for [t[superscript h]] or [flapped t] in bisyllabic nonce words. Consistent with previous studies, flaps were preferred before stressless syllables and [t[superscript h]] before stressed syllables, but the following phone also exerted a small degree of influence. Experiments 2 and 3 tested whether [t[superscript h]] or [flapped t] are associated with a particular syllable position in bisyllabic words. They demonstrate that [t[superscript h]] is favored in onsets, while [flapped t] is not consistently placed in either the onset or coda, nor is it generally ambisyllabic. These findings contradict analyses that posit syllable division as a conditioning factor in the appearance of [t[superscript h]] versus [flapped t]. Experiment 4 examined the pronunciation of 480 multisyllabic words from the TIMIT corpus. VCV was seen to favor [flapped t], while VCV favored [t[superscript h]]. In addition, flaps tend to be followed by syllabic sonorants and [t[superscript h]] by tense vowels. Because the following phones that influenced [t[superscript h]] and [flapped t] in Experiment 4 differ from those that were significant in Experiment 1, more research is necessary into the effect that following phones have on the appearance of [t[superscript h]] and [flapped t]. (Contains 6 tables and 13 footnotes.)