The Speed of Debt: When the Numbers Outrun the Nation

A collaboration between Lewis McLain & AI
(A revised article I wrote in 2007)


This isn’t another budget debate or partisan volley. It’s about speed — the speed at which the United States is piling on debt and the narrowing time we have to manage it.

I’ve pulled together data from Treasury’s Debt to the Penny database, the Monthly Statement of the Public Debt, the Federal Reserve’s cash-balance series, and the government’s own Financial Report. What they show is sobering — and I’m grateful to everyone who keeps these numbers public so we can study them together.


1. The Warning Is in the Speed, Not the Size

When we talk about a $38 trillion national debt, it’s hard for anyone to feel the difference between $36 trillion and $38 trillion. But here’s what matters: the U.S. added that last trillion in just 71 days.

Below is the table Treasury’s own data produces — the number of days it took to move from one trillion-dollar threshold to the next.

From ($T)To ($T)From DateTo DateDays Between
451993-04-011996-02-231,058
561996-02-232002-02-262,195
672002-02-262004-01-15688
782004-01-152005-10-18642
892005-10-182007-08-31682
9102007-08-312008-09-30396
10112008-09-302009-03-16167
11122009-03-162009-11-16245
12132009-11-162010-06-01197
13142010-06-012010-12-31213
14152010-12-312011-11-15319
15162011-11-152012-08-31290
16172012-08-312013-10-17412
17182013-10-172014-11-28407
18192014-11-282016-01-29427
19202016-01-292017-09-08588
20212017-09-082018-03-15188
21222018-03-152019-02-11333
22232019-02-112019-10-31262
23242019-10-312020-04-07159
24252020-04-072020-05-0528
25262020-05-052020-06-0935
26272020-06-092020-10-01114
27282020-10-012021-03-01151
28292021-03-012021-12-16290
29302021-12-162022-01-3146
30312022-01-312022-10-03245
31322022-10-032023-06-15255
32332023-06-152023-09-1592
33342023-09-152023-12-29105
34352023-12-292024-07-26210
35362024-07-262024-11-21118
36372024-11-212025-08-11263
37382025-08-112025-10-2171

It used to take years to add a trillion. Now it takes weeks. That’s the real warning light on the dashboard.


2. Shorter Maturities, Smaller Margin

Back in 1993 the average maturity of Treasury debt was roughly 12½ years.
Today it’s about 6 years, and roughly 22 percent of all marketable debt matures within one year.

Shorter maturities look smart when short-term rates are low, but they force the Treasury back to the market more often — like refinancing your mortgage every few months instead of every decade. If investors ever hesitate, even briefly, there’s an avalanche of maturing debt right behind it.


3. Why It Behaves Like a Ponzi — Even Though It Isn’t One

This isn’t fraud; it’s math.

Every month, new Treasury borrowing pays off old Treasury borrowing and covers the interest on what’s left. As long as new buyers keep showing up, the machine runs smoothly.

That’s also what keeps a Ponzi scheme alive — until confidence fades or inflows slow. The difference is that the U.S. government can tax, print, and regulate. But even governments can’t repeal arithmetic: if debt grows faster than income and the refinancing window gets shorter, confidence becomes the currency.


4. The “Trust-Fund” Holders — Borrowed from Ourselves

A surprising amount of the debt isn’t owed to the public at all — it’s owed to ourselves. About $7½ trillion of today’s $38 trillion total is intragovernmental debt: money that one part of the government has lent to another.

The biggest lenders:

RankTrust Fund / AccountHoldings ($ B)
1Other government accounts (aggregate)2,675
2Social Security – OASI Trust Fund2,466
3Federal Employees Retirement Funds904
4Medicare Trust Funds (HI + SMI)447
5Social Security – DI Trust Fund211
6Unemployment Trust Fund98
7Highway Trust Fund88
8Deposit Insurance Fund (FDIC)109
9Federal Housing Administration (FHA)165
10Smaller & legacy funds (Post Office, Airport & Airway, Railroad Retirement, etc.)< 60 each

Each fund holds special-issue Treasury securities — assets on its books, liabilities on the Treasury’s. They don’t have cash in vaults; they have receivables from the Treasury. When benefits are due, the Treasury must come up with cash — through taxes or by borrowing again from the public.


5. True Operating Cash — The Real Checkbook

So how much money does the federal government actually have to operate on?

Treasury’s Operating Cash Balance (OCB) — its checkbook at the Federal Reserve — tells us:

EraTypical Operating Cash Balance
2000–2007$20–50 B
2008–2014$100–300 B
2015–2019$300–400 B
2020 (COVID peak)$1.6 T
2021–2022$700–900 B
2023–2025$450–950 B fluctuating

The FY 2024 Financial Report listed $871 B in operating cash, while the Fed’s own TGA series showed about $940 B in early November 2025.

That sounds large — until you remember it sits beside $38 trillion in total debt.
It’s not solvency; it’s a buffer measured in weeks.


6. What the Speed Means

Here’s how the pattern looks through time:

EraAvg. Days per $1 TTypical WAMCharacter
1990s1 000–2 000 days12 yearsPredictable growth
2000–2008~650 days7–8 yearsModerate deficits
2009–2016160–600 days5–6 yearsCrisis & recovery
2017–2019200–330 days6 yearsLate-cycle looseness
2020–202528–263 days5–6 yearsAcceleration, pandemic, politics

The system now borrows faster and must refinance sooner — two lines on the same graph, both curving downward toward zero.


7. Why the Trust Funds Don’t Save Us

Social Security, Medicare, and federal pensions hold trillions, but they hold them as special Treasuries. When those are redeemed to pay retirees, the Treasury must find cash. That means the same public borrowing that funded the rest of government. In short, we have IOUs to ourselves — promises backed by the same overworked credit card.


8. Cash Flow, Confidence, and Collapse Risk

Operating cash around $800 B seems comfortable until you realize that roughly $8 trillion of marketable debt will mature within a year. That means Treasury is always just a few bad auctions away from a scramble — not because of insolvency, but because of timing. In financial systems, timing failures can look like insolvency long before real default occurs.


9. Shared Credit Where It’s Due

Much of this analysis builds on open Treasury and Federal Reserve data —
the Debt to the Penny dataset, the Monthly Statement of the Public Debt, the Financial Report of the United States Government, and the FRED time series for the Treasury General Account. Every citizen can look at the same numbers and come to their own conclusions. My goal here — and I hope yours too — is to keep those facts visible before they blur together.


10. The Takeaway

Debt itself is not immoral. It built our highways, won our wars, and carried us through a pandemic. But when the speed of borrowing outruns the time to repay, we trade stability for convenience.

In 1993, the U.S. had an average debt maturity of twelve years and a trillion-dollar increase every few years. Today, maturities average six years and a trillion arrives every couple of months.

That’s not a cliff yet — but it’s a downhill grade with failing brakes.

The danger isn’t only the size of the debt. It’s the speed at which it is accumulating.


Data sources: U.S. Department of the Treasury – Debt to the Penny, Monthly Statement of the Public Debt (Table FD-3, June 2025), Daily Treasury Statement, Financial Report of the U.S. Government (FY 2024), and Federal Reserve FRED series WTREGEN (Treasury General Account).

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