Commercial Paper vs. Treasury Bills: Credit Risk, Maturity, and Yield

A Treasury bill, or T-bill, is a short-term marketable security issued by the U.S. Treasury. Regular bill terms run from four weeks through 52 weeks. Bills generally pay no periodic coupon: an investor buys at a discount to face value, then receives face value at maturity. TreasuryDirect explains that the difference between the purchase price and face value is the bill's interest. See TreasuryDirect's Treasury bill overview.

Commercial paper (CP) is a short-term debt instrument issued by a corporation or financial institution to borrow money. Conventional corporate CP is often an unsecured promise by the named issuer to pay a stated amount on a specified date. Some CP is supported by collateral, a guarantee, a bank line, or another form of credit or liquidity support, so the label alone does not tell you the full structure. The Federal Reserve describes both the common discount format and occasional interest-bearing CP in its Commercial Paper manual.

Both instruments can be used for short-term funding or cash management, but they do not represent the same credit exposure. The term “money market” describes a broad market for short-dated borrowing and lending. It does not turn a Treasury bill, a corporate note, and a share in a money market fund into interchangeable products.

With a T-bill, the U.S. Treasury is the issuer and payer. With conventional unsecured CP, the company or financial institution named as issuer owes payment from its available resources. If that issuer cannot pay, a CP holder can lose some or all of the amount due. A short maturity does not remove issuer credit risk.

“Commercial paper is unsecured” is a useful description of many conventional issues, not a rule for every product carrying the CP name. Asset-backed commercial paper (ABCP) is issued through a program backed by assets such as receivables. The payment path can depend on collections from those assets, the program structure, and any credit or liquidity support. The OCC examiner's guide describes these structures and their support mechanisms. An asset pool is not the same as a simple guarantee: investors need to understand who owes each payment and what happens if collections, funding, or support fail.

Neither a short stated term nor a high credit rating makes an investment risk-free. T-bill prices may move before maturity, and investors face inflation, reinvestment, settlement, and other market risks. CP adds exposure to the issuer and potentially to collateral, program, and liquidity arrangements. A comparison should start with the legal issuer and payment structure rather than treating all short-term paper as cash.

TreasuryDirect lists regular T-bill maturities of 4, 6, 8, 13, 17, 26, and 52 weeks, with payment at maturity rather than scheduled coupon payments. A bill bought below face value therefore has one scheduled payment: face value on its maturity date. An investor who sells earlier receives a market price, which may be above or below the purchase price. The Treasury bill pricing page explains the discount and maturity payment.

CP is also short-term, but its exact term and cash-flow form depend on the issue. Many U.S. corporate issues are structured for terms of 270 days or less, and they often mature in less time; that convention is connected to securities-law exemptions and should not be mistaken for a universal definition of every short-term corporate note. A typical discount issue makes one payment at maturity. Some CP instead pays interest, and structured or asset-backed programs can have additional arrangements. Check the offering documents for the issue's dates, payment amount, extension or demand features, and support terms. The OCC guide explains that ABCP programs may repeatedly issue and roll maturing paper.

Because the repayment dates may be only weeks apart, a difference in maturity still matters. The investor's money is committed for a different period, and the issuer must meet its obligation on a different date. For an issuer that regularly refinances CP, the ability to sell new paper when old paper matures can also matter; that is one source of rollover risk.

T-bill auction prices are commonly described with a bank discount rate. TreasuryDirect gives the pricing formula as:

Price = face value × (1 − discount rate × days to maturity ÷ 360)

The discount rate uses face value as its reference amount and a 360-day year. It is not the same as the simple return measured against the cash an investor paid. For a bill purchased below face value, a simple 360-day annualized holding-period yield instead uses the purchase price in the denominator:

Simple annualized yield = (face value − price) ÷ price × 360 ÷ actual days held

The Federal Reserve's CP manual says CP is commonly issued at a discount, sometimes as interest-bearing paper, and calculated on a 360-day year. Quotes still need to be checked: a displayed rate may be a discount rate, a simple yield, or another market convention. A comparison is meaningful only when the day count, annualization, price basis, dates, and payment terms are aligned. TreasuryDirect's pricing explanation shows the bill convention.

Assume, only for illustration, that each instrument has $10,000 face value, 90 actual days to maturity, one payment of face value at maturity, and no fees or taxes. Further assume both are newly purchased at a discount quoted on the same 360-day bank-discount basis. Use a hypothetical 4.00% discount rate for the T-bill and 4.50% for the CP. These are invented inputs, not current quotes, forecasts, or recommendations.

For the T-bill, the assumed price is $10,000 × (1 − 0.04 × 90 ÷ 360) = $9,900. If paid as promised, the $100 difference between face value and price is the holding-period income. On the cash paid, the simple annualized yield using the same 360-day basis is $100 ÷ $9,900 × 360 ÷ 90, or about 4.04%.

For the CP, the assumed price is $10,000 × (1 − 0.045 × 90 ÷ 360) = $9,887.50. If paid as promised, the $112.50 difference is the holding-period income. The corresponding simple annualized yield on the price paid is $112.50 ÷ $9,887.50 × 360 ÷ 90, or about 4.55%.

The calculation isolates the arithmetic under matching assumptions; it does not say that an actual CP quote should exceed a T-bill quote by a fixed amount. Real securities can have different settlement dates, day counts, credit terms, issue structures, available prices, and transaction costs. A quoted discount rate also cannot be compared directly with a yield that uses purchase price in the denominator. Payment at maturity is assumed in the example, not guaranteed.

Treasury bills can be held to maturity or sold beforehand. An early sale uses the market price available at that time; changing interest rates, market conditions, and transaction costs can affect the amount realized. TreasuryDirect notes both holding and selling before maturity on its bill overview.

Commercial paper is generally arranged through dealers and over-the-counter markets rather than an exchange. The Federal Reserve's 2025 note says CP transactions occur in OTC markets with minimal secondary-market trading. Many buyers plan to hold an issue to maturity, so a holder who needs cash early may not find the same depth or terms available for a Treasury bill. Private-placement restrictions or issue-specific features may add constraints. Liquidity can differ across issuers and issues; “CP” by itself does not give a complete estimate of how easily a particular note can be sold. See the Federal Reserve's study of CP pricing and money-market fund flows.

An issuer that relies on repeated CP issuance may need buyers to purchase new paper to repay paper coming due. If funding conditions tighten or investors pull back, rolling the debt can become more difficult or expensive. A short maturity may limit some interest-rate exposure, but it concentrates attention on the next payment and on access to refinancing. An investor should distinguish a planned maturity payment from an ability to resell the security before that date.

No. A money market fund is a pooled investment that owns a portfolio of short-term securities; a fund share is an interest in that portfolio, not direct ownership of one specific T-bill or CP note. FINRA describes money market funds as investing in instruments that can include both Treasury bills and commercial paper, and it distinguishes the fund from the underlying securities. Read a fund's current holdings, investment policy, liquidity terms, and risks rather than assuming its name means it holds only Treasury bills. See FINRA's money market fund overview.

Directly holding a bill or CP note exposes the investor to that issue's own payment and maturity terms. A fund spreads assets across a portfolio and has its own share-price, liquidity, fee, and redemption arrangements. A fund may sell holdings or meet redemptions under rules that do not apply to an investor holding a single note to maturity. Fund shares are not deposits, and a money market fund is not interchangeable with a bank account or with a direct Treasury obligation.

Start by identifying the legal issuer, whether a CP issue is unsecured or asset-backed, any guarantor or liquidity support, and the exact payment date and amount. Next, confirm whether the instrument pays a discount at maturity or periodic interest. Then write down the quote convention, day-count basis, settlement date, time to maturity, and price denominator before converting one rate to another.

Also ask whether you expect to hold through maturity or may need to sell early. Check the issue's trading arrangements and any resale restrictions. For CP, consider both issuer credit and the ability to refinance if the borrower routinely rolls its short-term funding. For a T-bill, consider market-price movement before maturity and what happens when the proceeds need to be reinvested. A higher displayed rate alone does not reveal whether the difference compensates for credit, liquidity, maturity, or quote convention.

For related mechanics, see the guide to Treasury bill ladders and reinvestment risk and how to read Treasury auction results. Those articles cover bill cash-flow timing and auction data; neither replaces checking the terms and risks of a specific issue.