In case you have $6 trillion laying around . . .
From Frequently Asked Questions - 1.1 General Procedural Questions
I'm concerned about the public debt. Can I make a payment to reduce it?
Yes. You can make a contribution (gift) to reduce the public debt. Make a separate check payable to the "Bureau of the Public Debt." You can also enclose the check with your tax return. Please do not add this gift to any income tax you owe. You can send the check to the
Bureau of the Public Debt
P. O. Box 2188
Parkersburg, W.V. 26106-2188
You can deduct this gift as a charitable contribution on your next tax return if you itemize your deductions on Form 1040, Schedule A. If you owe tax, make a separate check for that amount payable to "United States Treasury."
Yeehaw! Sign me up! Err, wait, I already am.