In everyday speech, words are often produced with reduced pronunciation variants, in which segments are shorter or completely absent. We investigated whether word-final /t/ reduction in Dutch past-participles is affected by the ease of planning of the preceding word, and whether previously found morphological effects may actually be planning effects. We analyzed presence of 1369 /t/s and their durations in two speech corpora representing three speech styles. /t/ appeared more often absent and shorter if the past-participle followed a word that is highly predictable given the preceding context. Furthermore, /t/ was more reduced in irregular pastparticiples with a high frequency relative to the frequencies of the other inflected forms in the verbal paradigm, that is, in past-participles that can be selected more easily, and thus planned more quickly. Both effects were more pronounced in more spontaneous speech styles, which is as expected if the effects are driven by speech planning. These planning effects have to be incorporated in psycholinguistic models of speech production. Abstractionist models could, for instance, adapt the articulation level. Exemplar-based models have to incorporate planning as a factor influencing the choice of exemplar, or assume an articulation level that can modify the selected exemplar.