A 529 Plan is a type of investment account you can use for education savings, which is usually sponsored by individual states. Your earnings grow federally tax-deferred, qualified withdrawals are tax-free, and some states like Missouri and Illinois have other tax benefits as well.
Just about anybody can open a 529 account—parents, grandparents, other relatives, friends. As an account owner, you pick the investments and select the student beneficiaries. You can also receive a state tax deduction if you're a Missouri or Illinois resident.
You can make your payments to Vianney via SmartTuition and reimburse yourself from your 529 Plan OR make withdrawals from your 529 Plan, have the check made payable to St. John Vianney High School, and send the payment directly to Vianney.
Please ask your tax advisor how a 529 Plan can be used to pay tuition at St. John Vianney High School.