500metrics

Interest Expense on the Public Debt Outstanding · gross interest by kind of security

Which kinds of Treasury securities carry the most interest?

Treasury notes made up 37.3% of gross interest expense on the public debt in the 12 months to , Government Account Series 21.5% and Treasury bills 18.7%.

Share of gross interest expense in each kind of security, 12 months to each month-end

186 periods, Apr 2011 to Sep 2026The full height is 100%

Share of gross interest expense in each kind of security, 12 months to each month-end, Apr 2011 to Sep 2026
  • Other 0.0%
  • Government Account Series 21.5%
  • State and local government series 0.2%
  • Savings securities 0.3%
  • Floating rate notes 2.0%
  • Inflation-protected securities (TIPS) 6.8%
  • Treasury bonds 13.2%
  • Treasury notes 37.3%
  • Treasury bills 18.7%

Each band is one kind's share of the whole, the first kind at the bottom; the shares are ours, worked out from the Treasury's amounts. Pointing at a period shows its shares. Each year's end is under "The numbers behind the chart".

Observed .

Right now

Treasury notes made up 37.3% of gross interest expense on the public debt in the 12 months to , Government Account Series 21.5% and Treasury bills 18.7%.

The whole was $1.36T in the 12 months to .

See each year's shares

Over time

Over the year to , Treasury notes rose from 35.6% to 37.3%, and Treasury bills fell from 22.3% to 18.7%.

Since , Treasury bills rose from 0.8% to 18.7%, and Government Account Series fell from 47.0% to 21.5%.

See the shares year by year

OursOur arithmetic

The amounts are the Treasury's. A share is one kind's amount divided by the sum of all kinds, to one decimal, and is worked out by 500metrics.

Understanding interest by type of security

Where it stands today

Treasury notes made up 37.3% of gross interest expense on the public debtin the 12 months to.

How is this chart made?

Gross interest expense is the interest the Treasury records on all its debt, including the interest on Government Account Series that is credited to federal trust funds. It is not budget net interest, which leaves out what one part of the government pays another.

Read more

Interest expense is not the cash paid. On bills it is the discount spread over the bill's life, and on TIPS it includes the expense of inflation compensation, the rise in the principal.

The amounts are the Treasury's, in millions of dollars. Each share is the interest of one kind divided by the sum of all kinds in the same 12 months, worked out by 500metrics.

The numbers behind the chart

What share did each kind hold in the 12 months to the end of September in each year?16 rows, newest first
Share of gross interest expense on the public debt in each kind of security in the 12 months to the end of September in each year, newest first
12 months toTreasury billsTreasury notesTreasury bondsInflation-protected securities (TIPS)Floating rate notesSavings securitiesState and local government seriesGovernment Account SeriesOther
18.7%37.3%13.2%6.8%2.0%0.3%0.2%21.5%0.0%
22.3%35.6%13.0%5.9%2.3%0.4%0.3%20.2%0.1%
27.0%29.9%12.2%6.3%2.7%0.6%0.3%20.9%0.1%
20.7%28.4%13.8%7.9%3.2%1.0%0.2%24.5%0.1%
3.3%26.7%15.1%21.1%0.9%0.8%0.1%31.9%0.1%
0.8%33.5%17.4%16.4%0.2%0.6%0.2%30.8%0.1%
5.8%39.9%17.5%4.9%0.8%0.9%0.3%29.6%0.3%
9.5%34.9%15.4%6.4%1.6%0.9%0.2%30.9%0.3%
6.4%32.6%16.1%9.4%1.2%1.0%0.2%32.9%0.3%
2.7%34.1%17.7%6.8%0.7%1.1%0.2%36.4%0.3%
1.1%35.8%18.4%4.6%0.3%1.1%0.2%38.1%0.3%
0.3%37.0%19.1%3.0%0.1%1.4%0.3%38.3%0.5%
Show 4 more rows
12 months toTreasury billsTreasury notesTreasury bondsInflation-protected securities (TIPS)Floating rate notesSavings securitiesState and local government seriesGovernment Account SeriesOther
0.3%33.3%16.8%7.0%0.0%1.3%0.4%40.7%0.3%
0.5%33.6%16.0%6.6%0.0%1.4%0.6%40.9%0.3%
0.4%40.4%17.1%6.5%0.0%1.8%1.1%32.4%0.3%
0.6%31.1%12.1%7.9%0.0%1.2%1.3%45.5%0.2%

The table scrolls sideways; the first column stays in place.

How much was each kind, in millions of dollars?Millions of dollars of interest expense in the 12 months to the month-end
Millions of dollars of interest expense in the 12 months to the month-end, in each year, newest first
12 months toTreasury billsTreasury notesTreasury bondsInflation-protected securities (TIPS)Floating rate notesSavings securitiesState and local government seriesGovernment Account SeriesOtherAll kinds
254,122507,717179,81092,34726,6594,4912,717291,9336011,360,397
271,741433,798158,77272,24828,5724,6423,260246,3526401,220,025
306,434338,249138,69571,24030,9406,2963,367237,0307851,133,036
182,866251,044121,74270,05928,4468,9192,141216,428953882,598
23,599191,589108,506151,8856,4795,637980229,497573718,745
4,245188,32198,09892,3279183,4971,059173,353570562,388
30,397208,79391,68325,8603,9254,5781,369154,6651,497522,767
54,519200,33388,54936,6929,0505,2871,119177,2911,749574,589
33,306170,47084,08849,1256,1155,2021,216171,8771,618523,017
12,164156,49481,09231,1322,9935,0281,142167,0011,496458,542
4,788155,00979,57419,9511,1684,8311,021164,9241,384432,650
1,170149,04276,97512,2122025,4391,128154,2662,001402,435
Show 4 more rows
12 months toTreasury billsTreasury notesTreasury bondsInflation-protected securities (TIPS)Floating rate notesSavings securitiesState and local government seriesGovernment Account SeriesOtherAll kinds
1,165143,47172,48529,984395,4391,526175,3841,320430,813
1,876139,83366,70027,60305,7642,529170,1641,219415,688
1,536145,23561,59023,48406,3893,933116,5011,128359,796
2,787141,40555,18935,96005,6465,800206,5621,044454,393

The table scrolls sideways; the first column stays in place.

What do the figures leave out, and what are their dates?Limits and dates

What this number cannot tell you

  • Interest on Government Account Series is booked mostly in June and December, and a month of inflation compensation on TIPS can be negative, so each period adds twelve months. The table begins in May 2010, so the first period ends in April 2011.
  • Other holds interest on the Treasury's smaller public series (domestic, foreign and R.E.A. series), on matured debt and on the other minor entries. Savings bonds and state and local government series have a kind of their own.
  • A share is printed to one decimal, so a kind under 0.05 percent of the whole shows as 0.0%. A period that would need a month the table lacks is left out.

Dates

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