The aims of this study were to examine vocabulary scores of 5-year-old children who are deaf or hard of hearing (DHH), as well as the impact of early enrollment in specialized intervention on vocabulary outcomes. Receptive and expressive vocabulary scores were analyzed for 342 five-year-old children who are DHH enrolled in specialized listening and spoken language intervention programs. Regression analyses were utilized to examine the effects of age at enrollment on vocabulary outcomes. Overall, participants achieved scores within normal test limits on receptive and expressive measures of vocabulary. Children who enrolled in intervention prior to 28 months of age had better vocabulary skills at 5 years old. The findings support that children who are DHH can understand and produce vocabulary at skill levels commensurate with their typically hearing peers, regardless of severity of hearing loss. Results highlight the crucial impact of specialized programs on children’s lexical readiness to participate in general education settings by kindergarten.