The current study focused on gathering validity evidence for the use of an authentic formative assessment called Teaching Strategies GOLD (GOLD® ). Differential item functioning analyses were used with a large sample of young children (n = 32,063) to gather evidence that teachers use GOLD® developmental progressions in a consistent manner across sub-groups of children based on gender, race, and primary language spoken in the home. Nominal item difficulty classifications (Easy, Average, or Difficult) were the same for each group across nearly all sub-group comparisons and developmental progressions. For all progressions, across all developmental domains and across all group comparisons, the DIF magnitudes were negligible (≤.43). This study provided evidence that teachers are generally using GOLD® developmental progressions in a similar manner across the sub-groups of young children compared in this study.