I found the information from google search.

来源: 于 2025-12-23 18:24:55 [旧帖] [给我悄悄话] 本文已被阅读：次
Yes, you can transfer your son's unused 529 plan funds to an account for your grandchild without incurring taxes or penalties, provided certain conditions are met
. 
The key requirement is that the new beneficiary must be a qualified family memberof the original beneficiary (your son). The IRS's definition of a qualified family member is broad and includes: 
  • The son's children or descendants (which are your grandchildren).
  • Siblings or step-siblings.
  • Parents or ancestors.
  • First cousins.
  • Various in-laws (mother-in-law, brother-in-law, etc.).