529 應該沒有收入限製， 但是， 放進去有要求。查到的

Quick Summary

• There is no IRS annual contribution limit for 529 plans, but contributions above $19,000 per person ($38,000 for married couples) in 2025 and 2026 require filing a gift tax return.
• Most states offer tax deductions or credits on contributions, with limits on the deductible amount ranging from $500 to unlimited per year.
• Each state sets an aggregate lifetime limit (typically $235,000 to $600,000+) on total contributions per beneficiary.