A nonmarketable security is a debt instrument that its owner cannot sell, transfer or pledge to another investor; the only way to turn it into cash is to redeem it with the issuer on the issuer's terms. The term is used mainly for United States Treasury debt, where it covers savings bonds bought by households, Government Account Series securities held by federal trust funds, and State and Local Government Series securities bought by issuers of tax-exempt bonds.
Its opposite is a marketable security, such as a Treasury bill, note or bond, which is sold at auction and then trades freely in the secondary market at a price set by buyers and sellers. In general finance the phrase is sometimes used loosely for any asset without a ready market, such as shares in a private company, but in government debt statistics it has a precise meaning: the instrument is non-transferable by design.
Nonmarketable security in plain terms
Most government bonds are like concert tickets that can be resold: if you no longer want one, you sell it to someone else, and the price depends on demand that day. A nonmarketable security is more like a named, non-refundable-to-others voucher. It carries your name, nobody else can use it, and if you want your money back you must return it to whoever issued it.
That rule cuts both ways. You can never get a windfall by selling to an eager buyer, but you also never have to accept a low price in a panic. The issuer decides in advance what the security is worth on each date, so its value does not jump around with the market.
Types of US nonmarketable Treasury securities
The Treasury's Monthly Statement of the Public Debt splits federal debt into marketable and nonmarketable holdings. The main nonmarketable categories are:
- Government Account Series (GAS). These are held by federal trust funds and accounts, including the Social Security trust funds and federal employee retirement funds, which invest their surpluses in them.
- United States Savings Securities. These are the savings bonds sold to individuals, today the Series EE and Series I bonds, and earlier the Series E Savings Bond.
- State and Local Government Series (SLGS). Issued since 1972, these let issuers of tax-exempt municipal bonds park bond proceeds at rates that comply with federal arbitrage yield restrictions in section 148 of the Internal Revenue Code.
- Smaller series. These include Foreign Series and Domestic Series securities and the zero-percent certificates of indebtedness that TreasuryDirect accounts use to hold cash.
By value, GAS securities dominate. Debt held by federal government accounts, almost all of it in this form, stood at about $7.7 trillion of total public debt of roughly $39 trillion at the end of April 2026.
How they differ from marketable debt
Marketable Treasuries are priced by the market: their price falls when interest rates rise, and they can be used as collateral, for instance in a repurchase agreement. Nonmarketable securities have no secondary market price at all. Their redemption values follow schedules or formulas fixed by the Treasury, and GAS securities are normally redeemable at par whenever a trust fund needs cash. For individuals, the trade-off shows up in the rules: savings bonds cannot be cashed in the first 12 months, lose the last three months of interest if redeemed within five years, and can be bought electronically only up to $10,000 per series per person each calendar year.
This design gives savers protection from price risk at the cost of liquidity, and gives the government a stable, predictable source of funding that cannot be dumped on the market in a crisis.
History and policy role
The modern use of nonmarketable debt for households began with the Treasury's "baby bonds" of 1935 and expanded hugely in the Second World War. The tradable Liberty Bonds of the First World War had fallen below face value in 1920, hurting small savers; wartime savings bonds sold through the Payroll Savings Plan avoided that risk because their value could only rise. They became the core of American war bond finance.
Today nonmarketable debt matters most in government borrowing statistics and in fights over the federal debt limit. GAS securities count toward gross debt and the statutory limit but not toward "debt held by the public". When the limit binds, the Treasury uses so-called extraordinary measures, such as suspending new GAS investments by certain retirement funds, to create room for continued borrowing until Congress acts.
Outside the United States
Other governments sell non-transferable debt to households too. In the United Kingdom, National Savings and Investments offers Premium Bonds, which pay prizes instead of interest, and savings certificates; neither can be traded. Many emerging economies run similar retail savings schemes. The common thread is a savings-style product backed by the state, offering security of capital rather than market yield.