Intragovernmental holdings

Where the money comes from

Several federal programs are financed by dedicated taxes or contributions that, for long stretches, brought in more than the programs paid out. By law those surpluses cannot sit idle. They are invested in special, non-marketable Treasury securities, and the Treasury spends the cash like any other revenue. What remains is a legal claim of one part of the government on another.

The largest holders are the Social Security trust funds, followed by the military and civil service retirement funds and Medicare’s Hospital Insurance fund. Together they account for a smaller share of the national debt than debt held by the public; the live split on this site shows the current proportion.

Is it real debt?

This is one of the genuinely contested questions in debt accounting. One view holds that it is not debt in any meaningful sense: the government cannot default on itself, and the securities never reach financial markets. On that reading, debt held by the public is the only figure that matters.

The opposing view is that the obligation is entirely real, because the trust funds exist to pay benefits to real people. When a fund redeems its securities to cover a shortfall, the Treasury has to find the cash by taxing, cutting elsewhere or borrowing from the public. The IOU does not disappear; it turns into ordinary borrowing. Both positions are defensible, which is why this site shows the total and the split rather than choosing one.

Why the balance is shifting

As the population ages, Social Security now pays out more than its dedicated income and draws down its reserves to make up the difference. Each redemption reduces intragovernmental holdings while the Treasury borrows more from markets to pay. Total debt is unaffected by the switch, but more of it becomes publicly held, with market interest rates attached.