Sorry about the delay.
MAP 2-5 has some concordance with 6+, but it lacks the higher-level items (e.g., high school level math), which means that very high scores on the 2-5 typically see a small to moderate drop on retest with the 6+. In this case, scores in the upper 90s %iles are in the ceiling of the test, and, on the 2-5, likely have very high error bars compared with similar scores on the 6+. The 6+ retest would be expected to still find scores well above average, but possibly not in the upper 90s %iles.
