Language-minority students who enter the school system as English Learners (ELs) are expected, during their time as students, to be reclassified as Fluent English Proficient (R-FEP). Policy considerations tend to focus on the speed with which ELs are reclassified, with the specific goal of reaching R-FEP status quickly, sometimes within a predefined number of years. To reach R-FEP status, ELs often must attain test-based thresholds set by state or local policymakers. In this paper, we expand upon recent regression-discontinuity-based studies of reclassification policies (e.g., Matsudaira, 2005; Robinson, 2011) to examine the effects of policy changes in reclassification thresholds. We implement a series of “difference in regression discontinuity” designs to estimate these policies, and in the process, we also estimate the RDD-based effects. In our main analyses, as well as across several different specification checks, we find consistent evidence that a policy change, which shifted the test-based criteria for EL reclassification eligibility, had significant effects on high-school students’ subsequent English language arts (ELA) achievement (0.18 SDs) and graduation outcomes (13 percentage points). When a less rigorous version of the state English language proficiency (ELP) assessment was used as one of the key components of reclassification decisions, students in high school experienced negative effects on achievement in ELA and on graduation, suggesting they may have been reclassified before they had attained sufficient English proficiency to be successful in mainstream academic classes. When a policy change led to the ELP assessment becoming more difficult, and therefore, the criteria necessary to be reclassified more rigorous, high school students experienced no effect of reclassification on later outcomes, suggesting students were reclassified at an appropriate point in their educational trajectories. This research has implications for various policies affecting ELs, including how reclassification criteria under new Common Core State Standards-aligned assessments should be established.