I had a similar question a couple of months ago. Here is the link to my post.

http://giftedissues.davidsongifted....st_Math_Result_Interpret.html#Post224851

You may find some useful information from the responses. My DS7 (in first grade) took the K-2 MAP test in November and his scores put him at 99%. However, with that score and percentile, it was hard to tell which grade level he's really in. I am currently working with the school to have an accelerated plan for him. To determine which grade level he's in, they had him taking the MAP test 2-5 for math (scored 199), which put him right at the middle of school year for third grade (that's what the school told me). So I went online and checked myself. From the below chart, you can see that his score is at grade level for 3rd grade for the winter MAP test.

http://schools.cms.k12.nc.us/eastoverES/Documents/ACPS-MAP%20Parent%20Brochure.pdf

HTH