For DRA, you can work at home easily to improve his score. DRA is heavily focused on summarizing the plot and requires students to be very specific in details. A kid can jump several reading levels JUST by remembering to use the main character's name several times. While in normal conversation you'd say "Bob went to the store. Then he bought some milk," for DRA you want him to say "Bob went to the store in the afternoon. Then BOB bought some 1% milk." That alone can make a big difference.
The other downside to DRA is that students in 3rd or 4th grade or above are required to write their answers. That works out fine if you're a 4th grader, but if you are a kindergartener reading at a 4th grade level, it's not the same. My son's school agreed to let him keep giving the answers orally until his age matched his reading level :-) Maybe you can work with yours!
