The stability of annual normal curve equivalent (NCE) on the Iowa Test of Basic Skills over a period of six years was established in a previous study of status (position within a reference group). This study investigated the relationship between status stability and student achievement level. Third grade students in a suburban school district who continued through grade 8 in the same class, formed three cohort groups (n=153, N=148, n=148) for this investigation. Raw scores from six consecutive years were converted to percentile ranks, using national norms, and were then transformed to normal curve equivalents for the Reading Comprehension subtest and the Total Mathematics score. Correlations between means and variances suggested a non-linear relation. When achievement levels were blocked into deciles, the within-decile variation was very large when compared to the means, and obscured any relation between achievement level and within-subject variation, although a tendency toward linearity was suggested by plotting the mean variation within deciles for Reading Comprehension. (Author/BS)