Essentially,
there is no federal IRS limit to the amount. It can all be done in one year or
multiple years. There is no federal deduction for making a contribution. States
may have a limit ($300,000) and most states allow a deduction for a
contribution and the Uncle gets the deduction even though the child is not his
dependent. The state deduction is limited (see http://www.savingforcollege.com/compare_529_plans/index.php?page=compare_plan_questions&plan_questio...
) but there is usually a roll over provision.
In a sense there is a federal limit of $70,000
to avoid a gift tax return. But, "Gift Tax" is
somewhat of a misnomer. Even though a gift tax return may be
required, very few people ever actually pay federal gift tax. The purpose of the
gift tax return is usually only to document a reduction in the allowable estate
tax exemption.
See https://turbotax.intuit.com/tax-tools/tax-tips/Tax-Planning-and-Checklists/The-Gift-Tax-Made-Simple/...
Reference: https://us.axa.com/goals/saving-for-college/articles/529-plans-contributions-withdrawls.html
