This paper presents and discusses implications for the phonology-phonetics interface that can be drawn from three of our studies on coarticulatory development across childhood. Vocalic coarticulation towards the left (anticipatory) as well as towards the right side (carryover) was investigated in children between 3 and 9 years of age as well as in adults. To monitor horizontal tongue movements during pseudoword production, we used ultrasound tongue imaging. Our data provides evidence for a developmental decrease of coarticulation degree both in anticipatory as well as in carryover coarticulation that cannot easily be explained by look-ahead models positing complex translation mechanisms between discrete phonological and dynamic articulatory units. Instead, we argue that the developmental decrease as well as a finding of discontinuous vocalic anticipation in children can best be modeled within the coproduction framework, and therefore Articulatory Phonology.