The current study examined whether Head Start children who experienced a high-quality preschool intervention, "Exceptional Coaching for Early Language and Literacy" ("ExCELL"), as three-year-olds began the subsequent pre-kindergarten (or four-year-old) year with stronger language and literacy skills than same-age peers who entered "ExCELL" in pre-kindergarten, as well as whether any differences remained at the end of the pre-kindergarten year. A total of 159 Head Start preschoolers participated, including 88 four-year-olds who had 1 year of "ExCELL" and 71 four-year-olds who had participated in "ExCELL" for 2 years. All children were assessed on language and literacy measures assessing vocabulary, alphabet knowledge, and phonemic awareness. Results showed that children who experienced "ExCELL" at age 3 had stronger vocabulary, sound awareness, and alphabet skills at the start of the pre-kindergarten year than peers who were new to the programme. However, there were few differences between these groups in their learning over time, and they concluded the pre-kindergarten year on equal footing. Thus, two years (at ages 3 and 4) of participation in the "ExCELL" intervention was not associated with better early-reading-related outcomes than one, pre-kindergarten year (at age 4) alone.