max time to undertake travel on B-2

[galexmaverik]

Hi,
My parents applied for and got their B-2 to come visit me here. The visa is for 10 years, multiple-entry. Is there a maximum duration of time within which they have to undertake their travel? In other words, if they dont travel within 3 months or something, will the visa automatically expire, even though it is 10-yr?

Thanks.

 

[vault]

Your parents can travel anytime before the expiration of the visa.