Yes, all 9mm Kahr magazines will work in all 9mm Kahr's... The same goes for the .40 Kahr's.
Of course you can't use the factory 6 round "flush" MK9/P9 Covert/PM9 mag in a K9/P9/E9/T9, but you can do it the other way around.
Here's a picture of my PM9 with a Pro-Mag 10 rounder installed: