This paper creates a novel link between research on linguistics and education by discussing what we know about the sound system of heritage language users of Spanish and how these findings can inform practices implemented in heritage Spanish courses in the USA. First, we provide an overview of terminology associated with heritage language research, situating heritage Spanish programs within the educational context of the USA, and explaining why heritage Spanish phonetics and phonology remain relatively unexplored. Next, we delve into previous linguistic research on the heritage Spanish sound system in terms of individual vowels and consonants, as well as at the level of intonation, rhythm, and stress, while highlighting any observed differences between the system of heritage Spanish and those of Spanish speakers of other backgrounds. Finally, motivated by the phonetic/phonological insight of previous work, in addition to existing pedagogical and curricular research on heritage Spanish, we consider how and why the inclusion of specific types of sound-system-based commentary and practice in the educational experience of heritage users of Spanish could be beneficial.