I would have to guess that for some purposes you would use his age and for others you would use what he has been taught. Are you filling out an Iowa Acceleration Scale to consider further skips?
Grinity
I was actually just trying to figure out what the tests meant.
Re: further skips. I find myself thinking "No more skips!" as regards him.

But obviously I'll kep my mind open. That said, I'm not convinced he'll need another one.
I kind of think that skips may work best/be easiest in the lower grades as a rule of thumb but not an absolute (?). Though given the US homework culture, it might be easier on the kid to skip, say 10th grade. Comments welcome on this idea.
He's in 6th now with extra math acceleration. One benefit of the testing was that when I suggested skipping 7th grade math, it was not viewed as an insane suggestion. Phew.
Perhaps I'll start a thread called
"Oh dear, seventh grade math."DD5's teacher is trying her out in second grade spelling (she's also doing second grade reading). This is nice. If it's too hard, DT (dear teacher) said she can just put her back in 1st grade spelling. Talk about open-minded....
Val