My doctor (also WA) was concerned that ds wasn't retractable at his three year appointment too. It must be on their check list. Although our doctor just recommended making sure that the foreskin can be stretched away from ds's body. He does this plenty on his own so I let it at that. She suggested steroid cream if it didn't retract "soon".
However, I can see the foreskin open when ds urinates, so I know that it CAN and will eventually when he is ready. We've had no problems in the year since. DH said he didn't retract until 9 or 10 (remembers it quite clearly). So I forgot to worry
This year at the 4 year appointment there was no messing with the penis and the same doctor seemed to forget that he "should be retractable". It wasn't even mentioned and I didn't say anything either.
I wouldn't personally treat at this age, although if you are still concerned watch closely when he urinates and you may see it open. I know that made me feel better, that there wasn't anything anatomically "wrong".