And is there a particular vesting date, or trigger event?
I ask because when people ask questions like yours,
it's often because the beneficiary has, say,
reached the age at which they can receive (say, turning 21),
or because some event has happened that had to happen before they got anything (say, they got married).
Bit hard to say for sure without seeing the paperwork.
In general though, and with out referring to your specific case...
if all the conditions of "vesting" have been met,
then it typically becomes his to do what he wants with it.
Check the wording...
There's a difference between something like "He gets when he turns 21, as long as he uses it to buy a house"
and "He gets it when he's 21."