This study examined how long it typically takes English learner students to become proficient in English and how this time differs by student characteristics, such as gender, home language, or initial proficiency in English. The authors analyzed state data for 16,957 English learner students who entered kindergarten between 2005/06 and 2011/12 in seven cohorts. The students attended seven school districts that comprise the Road Map Project, an initiative designed to double the number of students in South King County (Washington) who are on track to graduate from college or earn a career credential by 2020. The study looked at five language groups in the region, each of which comprises at least 3 percent of the total sample: Spanish, Vietnamese, Somali, Russian and Ukrainian combined, and Cantonese and Mandarin Chinese combined. All other languages, 160 in total, were combined into an “other language” category. The findings show that students who entered kindergarten as English learners took a median of 3.8 years to be reclassified by Washington state as former English learners. Those who entered kindergarten with advanced English language proficiency were more likely to be reclassified than English learner students with basic or intermediate English proficiency. Also, female English learner students were more likely to be reclassified than male English learner students. Speakers of Chinese, Vietnamese, and Russian and Ukrainian were more likely to be reclassified than Somali or Spanish speakers. In addition to contributing to the research base, the study findings may be of interest to state education agencies as they create new targets and standards for English language proficiency. State agencies may wish to consider taking initial English language proficiency into account when determining appropriate targets for federal accountability measures, for example by setting longer expected times to reclassification and providing additional support to students entering school with basic or intermediate levels of English language proficiency. Many states are also implementing new standards for college and career readiness and overhauling their assessment and accountability systems, both of which involve setting additional targets for English learner students. A better understanding of the factors related to variation in time to proficiency may allow states to establish targets that take particular factors, such as initial English language proficiency, into account.