Structure of US Treasury Bills, Notes, and Bonds

The U.S. Treasury market is the deepest, most liquid bond market on Earth — and it isn't close. As of Q4 2025, $28.9 trillion in marketable Treasury debt sits outstanding (SIFMA), forming the backbone of global fixed-income pricing, central bank reserves, and the "risk-free" benchmark against which virtually every other asset is measured.

That $28.9 trillion breaks down into distinct instruments that serve fundamentally different purposes. T-notes dominate at roughly $14.8 trillion (51% of marketable debt), followed by T-bills at $6.2 trillion (21%), T-bonds at $4.8 trillion (17%), TIPS at $2.0 trillion, and floating rate notes at $0.7 trillion. These aren't interchangeable. Each type serves a different investment horizon, generates returns through a different mechanism, and exposes you to a different mix of risks.

Understanding the structural differences — how a discount instrument works versus a coupon-bearing note, why auction mechanics matter, and what the yield curve is actually telling you — is what separates investors who use Treasuries strategically from those who treat them as an undifferentiated "safe" allocation.

TL;DR: Treasury bills, notes, and bonds differ by maturity, how they pay returns, and the risks they carry. Bills (under 1 year) sell at a discount with no coupon. Notes (2–10 years) and bonds (20–30 years) pay fixed semiannual coupons. Matching the right instrument to your time horizon and understanding auction pricing are the keys to using Treasuries effectively.

What Actually Separates Bills, Notes, and Bonds (And Why It Matters)

The distinctions here aren't cosmetic — they determine how you get paid, when you get paid, and how much price risk you carry while waiting.

Treasury Bills are the simplest instruments in the lineup. They mature in 4, 8, 13, 17, 26, or 52 weeks, pay no coupon whatsoever, and generate returns entirely through the discount mechanism: you buy at less than face value and receive the full face value at maturity. The difference is your profit. Weekly auction sizes in early 2026 are enormous — $80 billion for 4-week bills, $85 billion for 13-week bills, and $70 billion for 26-week bills (TreasuryDirect). That volume reflects both government financing needs and massive institutional demand for short-term liquidity instruments.

Treasury Notes occupy the medium-term space with maturities of 2, 3, 5, 7, and 10 years. Unlike bills, notes pay a fixed coupon semiannually — you receive half the annual coupon rate every six months until maturity, then get your principal back. The February 2026 quarterly refunding included $42 billion in 10-year notes (U.S. Treasury Quarterly Refunding Statement). Notes are the workhorse of the Treasury market, accounting for over half of all outstanding marketable debt, because their maturities align with the planning horizons of pension funds, insurance companies, and individual investors building intermediate-term portfolios.

Treasury Bonds stretch to 20-year and 30-year maturities, also paying fixed semiannual coupons. The February 2026 refunding included $25 billion in 30-year bonds. These are the instruments most sensitive to interest rate changes (more on that in the risks section), which makes them simultaneously the most rewarding in falling-rate environments and the most punishing when rates rise.

Three additional instruments round out the marketable Treasury universe:

TIPS (Treasury Inflation-Protected Securities) adjust their principal based on changes in the Consumer Price Index (CPI-U), with a fixed-rate coupon paid semiannually on the adjusted principal. The sample 10-year TIPS real yield in February 2026 sits around 2.10% — meaning you earn 2.10% above whatever inflation turns out to be. That's the purest measure of real return available in a government-backed security.

Floating Rate Notes (FRNs) carry a 2-year maturity with a coupon that resets weekly based on the most recent 13-week T-bill auction high rate plus a fixed spread. They give you short-term rate exposure in a longer-dated wrapper.

STRIPS (Separate Trading of Registered Interest and Principal of Securities) aren't a separate issuance — they're the result of stripping a T-note or T-bond into individual zero-coupon components that trade separately. Each coupon payment and the final principal become their own tradeable security.

The minimum purchase across all types is just $100 on TreasuryDirect ($1,000 increments in secondary market lots), which means individual investors face no meaningful barrier to entry.

To put the current yield landscape in context, here's a February 2026 snapshot across maturities: 4-week bill discount rate: 4.230%, 13-week bill: 4.155%, 2-year note: 3.98%, 10-year note: 4.50%, 30-year bond: 4.68% (U.S. Treasury Daily Yield Curve Rates). Notice that the 2-year note actually yields less than the shortest bills — the shape of the yield curve matters, and we'll return to why.

How Auctions, Pricing, and the Yield Curve Work in Practice

Treasuries don't trade like stocks. The primary market runs through a structured auction process managed by the Treasury Department, and understanding the mechanics gives you an edge over investors who simply accept whatever their broker offers in the secondary market.

Two types of bids exist at every Treasury auction. Noncompetitive bids specify only a dollar amount (up to $10 million per auction per bidder) — you agree to accept whatever yield the auction determines, and in return you're guaranteed a full allocation. This is what most individual investors should use. Competitive bids specify both a yield and a dollar amount; you might get exactly what you want, you might get partially filled, or you might get shut out entirely if your target yield is below the clearing rate. Primary dealers, institutional investors, and hedge funds dominate the competitive side.

When-issued (WI) trading begins between the auction announcement date and the settlement date, before the security has been formally issued. This creates a pre-auction price signal — essentially a market consensus on where the auction should clear. Watching the WI market gives you a read on demand conditions before committing capital.

Settlement now runs at T+1 for bills, notes, and bonds alike (following the 2024 SEC rule change that compressed the settlement cycle). That's one business day from trade to delivery.

One of the most common sources of confusion is the difference between discount rate and bond equivalent yield (BEY) on T-bills. The discount rate — the number typically quoted at auction — calculates return based on face value using a 360-day year. The BEY recalculates the same return based on purchase price (which is lower) using a 365-day year. The result: the BEY is always higher than the discount rate. A 4.200% discount rate, for example, translates to a 4.351% BEY (as the worked example below demonstrates). Why this matters: if you're comparing a T-bill return to a T-note coupon yield, you must use BEY, or you're understating the bill's true return.

The par yield curve — published daily by the Treasury for maturities from 1-month through 30-year — shows the yields at which securities of various maturities would trade at face value. Its shape tells you what the market collectively expects about future rates, growth, and inflation. A normal upward-sloping curve signals expectations of continued growth. An inverted curve (short rates above long rates) has historically preceded recessions.

Bid-to-cover ratios serve as the market's demand thermometer. An illustrative recent 10-year note auction showed a bid-to-cover of 2.45 — meaning total bids were 2.45 times the amount of securities offered. Higher ratios indicate stronger demand; a sharp drop can signal waning appetite for duration risk.

For scale, the Q1 2026 quarterly refunding announced $125 billion in coupon securities (U.S. Treasury Quarterly Refunding Statement). These announcements move markets because they signal the government's borrowing trajectory and the supply of duration being pushed into the market.

A revealing historical episode illustrates how auction dynamics interact with fiscal policy: after the 2023 debt ceiling resolution, the Treasury needed to rapidly rebuild the Treasury General Account (the government's checking account). The result was approximately $1.4 trillion in net new T-bills issued between June and September 2023, temporarily pushing the T-bill share of outstanding debt above 22% (U.S. Treasury Monthly Statement of the Public Debt). That flood of short-term supply absorbed liquidity from money market funds and reshaped the maturity profile of the entire Treasury market in a matter of months.

Worked Example — Pricing a 26-Week T-Bill at Auction (And Why the Math Matters)

Here's where the rubber meets the road. You submit a noncompetitive bid for $10,000 face value of a 26-week (182-day) T-bill, and the auction clears at a 4.200% discount rate. What do you actually pay, what do you earn, and how does it compare to coupon-bearing alternatives?

Step 1: Calculate your purchase price.

The discount rate formula:

Purchase Price = Face Value × (1 − (Discount Rate × Days to Maturity / 360))

Plugging in: $10,000 × (1 − (0.0420 × 182 / 360)) = $10,000 × (1 − 0.02123) = $10,000 × 0.97877 = $9,787.67

You pay $9,787.67 today for a security that returns $10,000 in 182 days.

Step 2: Calculate your dollar profit.

$10,000.00 − $9,787.67 = $212.33

That $212.33 is your entire return — no coupon payments along the way, just one lump sum at maturity.

Step 3: Convert to bond equivalent yield.

BEY = (Discount / Purchase Price) × (365 / Days to Maturity)

($212.33 / $9,787.67) × (365 / 182) = 0.02169 × 2.00549 = 4.351%

Step 4: Understand the gap.

The 4.200% discount rate becomes a 4.351% bond equivalent yield — a difference of 15 basis points. Two factors drive this gap: (a) the return is calculated on the lower purchase price ($9,787.67) rather than face value ($10,000), which inflates the percentage, and (b) the BEY uses a 365-day year versus the discount rate's 360-day convention (per TreasuryDirect.gov pricing methodology).

The point is: this conversion isn't academic trivia — it's essential whenever you compare T-bill returns to T-note or T-bond coupon yields. Ignoring it means systematically understating what short-term bills actually earn relative to longer-dated alternatives.

Risks, Limitations, and the Tradeoffs You're Actually Making

"Risk-free" is a misnomer that trips up even experienced investors. Treasuries carry no credit risk (the U.S. government controls its own printing press), but they carry plenty of other risks that vary dramatically by maturity.

Interest rate risk is the dominant concern for notes and bonds. When yields rise, existing fixed-coupon securities lose market value — the longer the maturity, the steeper the loss. A 1-percentage-point increase in yield reduces the price of a 10-year note by approximately 8% and a 30-year bond by approximately 17%. T-bills, with maturities under a year, face minimal price risk because they're so close to maturity that rate moves barely affect their present value. The practical takeaway: if you might need to sell before maturity, duration matters enormously.

Inflation risk works in the opposite direction from what most people expect. Fixed-rate bills, notes, and bonds offer no principal adjustment for inflation. If you lock in a 4.50% yield on a 10-year note and inflation averages 5% over that period, your real return is negative. This is precisely what TIPS are designed to solve — that 2.10% real yield on 10-year TIPS means you earn 2.10% above whatever CPI-U delivers, regardless of the inflation path.

Reinvestment risk is the silent cost of staying short. An investor rolling 4-week bills at 4.230% today has no guarantee of similar rates at maturity. If the Fed cuts aggressively (as happened in 2020), you could find yourself reinvesting at 0.10% within months. Longer-term notes and bonds lock in a rate — which is a benefit when rates fall and a trap when rates rise. There's no free lunch here, only different risk profiles.

Liquidity variation catches investors off guard during stress periods. On-the-run Treasuries (the most recently issued securities at each maturity point) trade with tight bid-ask spreads and deep order books. Off-the-run issues — functionally identical in credit quality — can see spreads widen dramatically when markets seize up. During the March 2020 Treasury market dislocation, 10-year yields swung from 0.54% to 1.18% in a single week, bid-ask spreads on off-the-run Treasuries widened to 5–10 times normal levels, and the Federal Reserve purchased over $75 billion in Treasuries per day to restore functioning (Federal Reserve Bank of New York). The "safest" market in the world can still become illiquid in a crisis.

Opportunity cost is the long-run tradeoff nobody discusses at the point of purchase. Treasury yields consistently trail equity returns over multi-decade horizons. Holding long-duration bonds in a rising-rate environment can produce negative total returns for extended periods — not just underperformance, but actual losses if you need to sell before maturity.

A historical signpost worth remembering: on August 14, 2019, the 2-year note yield (1.634%) exceeded the 10-year note yield (1.623%) — the first inversion since 2007 (FRED). That inversion preceded the 2020 recession. The yield curve shape isn't a crystal ball, but inversions have preceded every U.S. recession for the past five decades. When short rates exceed long rates, the bond market is telling you something about growth expectations — and historically, it's been worth listening.

Your Treasury Buying Checklist (The Practical Steps)

Before committing capital to any Treasury security, work through these items:

• Match maturity to your actual horizon. T-bills for money you need within a year. T-notes for 2–10 year goals. T-bonds only if you genuinely plan to hold 20–30 years (or are making an active duration bet).

• Choose your bid type deliberately. Use noncompetitive bids for certainty of fill (up to $10 million per auction). Use competitive bids only if you have a specific target yield and can accept the risk of being shut out.

• Always convert T-bill discount rates to bond equivalent yields before comparing returns with coupon-bearing notes and bonds. The discount rate understates true return.

• Check the Treasury auction calendar at TreasuryDirect.gov for upcoming auction dates, announcement dates, and settlement dates. Timing matters if you're managing cash flows.

• Evaluate TIPS if inflation protection is your priority. A 2.10% real yield means 2.10% above inflation — compare that to the breakeven inflation rate implied by nominal yields to decide which bet you're more comfortable making.

• Read the auction results. Review the bid-to-cover ratio and the tail (the difference between the high yield and the when-issued yield) from recent auctions to gauge whether demand is strengthening or softening.

• Remember the tax treatment. Treasury interest is exempt from state and local income tax but fully subject to federal income tax. For investors in high-tax states, the after-tax advantage over comparable corporate or municipal bonds can be meaningful.

• Monitor the yield curve shape — normal, flat, or inverted — as a signal for economic expectations and to inform your maturity selection. When the curve inverts, extending duration carries different risk characteristics than when it slopes steeply upward.

The durable lesson: Treasuries aren't a single asset class. They're a spectrum of instruments with distinct structures, return mechanisms, and risk profiles. The investor who treats a 4-week T-bill and a 30-year bond as interchangeable "safe" holdings is taking risks they haven't measured. Match the instrument to the purpose, understand the pricing mechanics, and let the yield curve inform — but not dictate — your decisions.