Select Treasury Bills or Notes for Short-Term Cash

# T-Bills vs. T-Notes: Aligning Maturity Profiles with Liquidity Needs

We treat the choice as a duration-matching problem, not a return-maximization problem. Both instruments carry the full faith and credit of the U.S. government. Both are exempt from state and local income tax. The differences live in the maturity ladder, the cash-flow structure, and the price behavior on the secondary market. Below: the mechanical tests we run, the data points that drive the verdict, and the conditions under which each instrument passes.

The Mechanics of Maturity: Matching Cash Horizons to Treasury Instruments

Treasury Bills are issued at six maturity points: 4, 8, 13, 17, 26, and 52 weeks. Treasury Notes come in five terms: 2, 3, 5, 7, and 10 years. The two instruments do not overlap. There is no 18-month Treasury, no 14-month Treasury. This non-overlap is the first filter when an investor selects Treasury Bills or Notes for short-term cash.

If your cash need falls inside a 12-month window, the universe is T-Bills. If your horizon extends beyond 12 months, T-Notes enter the field. Investors who force-fit a T-Note into a 6-month window invite price risk on the exit. Investors who stuff 18 months of expected liability into a rolling T-Bill ladder introduce reinvestment risk at every 13-week rollover.

The maturity match is a binary test. There is no ambiguity at the boundary cases (13-month horizon, 14-month horizon) other than whether you accept the rollover cost of the T-Bill ladder for the first two months of the T-Note term. In our framework, the T-Bill ladder passes for any horizon up to 12 months. The T-Note passes for any horizon from 24 months upward. The 13-to-23-month band is a structural gap: ladder short T-Bills, or accept the duration of a 2-year T-Note.

One practical note on the ladder mechanics. A rolling T-Bill program means you are reinvesting principal every 4, 13, or 26 weeks. Each rollover is a new auction entry or a secondary-market purchase, each with its own settlement date and funding requirement. The operational overhead is modest but real: auction schedules must be tracked, reinvestment amounts must be calculated, and the cash must be available on settlement day. For an investor managing a $50,000 cash reserve across three maturities, this is a quarterly task. For a $5 million reserve, it is a monthly discipline. The T-Note, by contrast, is a single purchase with a fixed coupon schedule and no reinvestment decision until maturity. That simplicity has value beyond the yield curve.

The selection is a duration-matching problem, not a return-maximization problem. Both instruments are backed by U.S. sovereign credit.

Discounted Yields vs. Semi-Annual Coupons: How Returns Are Realized

A T-Bill does not pay a coupon. It is sold at a discount to par, and the investor's return is the difference between the discounted purchase price and the $100 face value received at maturity. The quoted yield is a function of that discount and the time to maturity. There are no interim cash flows. The position sits until par returns.

A T-Note pays interest every six months. The coupon is set at issuance and is paid on the same schedule for the life of the note. At maturity, the investor receives the final coupon plus the $100 par. The cash-flow profile is fundamentally different: regular income versus terminal lump sum.

Consider the mechanics on a concrete example. A 26-week T-Bill purchased at $97.50 returns $100 at maturity — a $2.50 gain on a six-month holding period, annualized to roughly 5.1% on a bank-discount basis. No checks arrive in between. The $2.50 is locked inside the price until term. A 2-year T-Note issued at par with a 4.50% coupon pays $2.25 per $100 face every six months — four payments over the life of the note, plus the return of principal at maturity. The investor in the T-Note sees cash twice a year. The investor in the T-Bill sees nothing until the end.

For a cash reserve that must remain liquid and untouched, the T-Bill structure is cleaner. No reinvestment decisions, no coupon timing, no reinvestment-rate risk on interim cash flows. The trade-off is that the entire return is realized at maturity. For a portfolio that wants to generate income while parking capital, the T-Note's semi-annual coupons deliver usable cash every 180 days.

The mechanical point: if you do not need the income, do not collect it. Reinvesting T-Note coupons at sub-market rates until the full position matures is a structural drag on returns. If coupons land in a sweep account earning 0.01% while the note yields 4.50%, that drag compounds. Over a 10-year T-Note, the reinvestment of 20 coupon payments at below-market rates can shave 15–30 basis points off the effective yield, depending on where rates sit during the holding period. If you need the income, the T-Note is the only option of the two, because T-Bills produce no interim cash.

Navigating Interest Rate Risk in the Secondary Market

A Treasury held to maturity pays par. Default risk is effectively zero for U.S. sovereign paper. This is the only risk-free condition. Any sale before maturity introduces price risk, and the magnitude of that risk scales with duration.

T-Bills have durations at or below 0.5 years. A 4-week T-Bill has a duration close to zero. A 52-week T-Bill sits near 0.5. Rate moves of 25 basis points produce measurable but small price changes. In our stress tests, a parallel 100 bps shift in the yield curve moves a 52-week T-Bill's price by less than 0.50%. The same shift on a 10-year T-Note moves the price by roughly 7–8%.

The T-Note duration range is the real issue. A 2-year T-Note carries a duration near 1.9. A 10-year T-Note carries a duration near 8.5. If you must liquidate a 10-year position two years into the term and rates are 150 bps higher than at purchase, you are looking at a price decline in the 12–15% range. That is not a theoretical number. It is the math of modified duration applied to a parallel yield-curve shift.

Here is the sensitivity matrix that drives the verdict on secondary-market exits:

The verdict on rate risk: T-Bills pass the secondary-market-exit test for any plausible rate move inside their maturity window. T-Notes pass only if the position is held to maturity. If the exit date is uncertain, T-Notes fail the stress test. This is the most common mistake we observe in practice: investors buy a 5-year T-Note for "cash management," then face an unexpected liability at year three, and discover that "cash equivalent" and "mark-to-market loss" can coexist in the same position.

Inflation is the second risk. Both instruments pay a fixed nominal return. If CPI runs above the yield at issuance, the real return is negative. We do not forecast inflation. We note that locking nominal cash flows for 2–10 years carries an inflation premium that the current yield curve may or may not compensate. Short T-Bills re-price every 13 or 26 weeks, which mitigates this exposure. Long T-Notes do not.

A 10-year T-Note sold at year two in a rising-rate environment is not a cash instrument. It is a duration bet you did not intend to make.

Tax Efficiency and the Federal-State Income Tax Split

Federal income tax applies to both T-Bill and T-Note income. State and local income tax does not. This is the cleanest tax structure available in U.S. fixed income, and it is identical across the two instruments.

The discount on a T-Bill is treated as ordinary interest income for federal purposes, taxable in the year the bill matures, or in the year of sale if sold before maturity. This creates a phantom-income issue for T-Bills purchased at a deep discount: the IRS requires the holder to accrue the discount as income over the holding period, even though no cash changes hands until maturity. For a 52-week T-Bill bought at $95, the $5 discount is reportable income for the tax year in which the bill matures, regardless of whether the investor sold it in January or held it to December. T-Note coupon income is taxable in the year received, which is straightforward — cash arrives, income is reported.

For investors in high state-tax jurisdictions (CA, NY, NJ, OR), the exemption is material: a 9–13% state rate is permanently eliminated from the tax bill. On a $100,000 T-Note position yielding 4.50%, the state-tax savings alone amount to $405–$585 per year, depending on the bracket. Over a 5-year holding period, that exemption accumulates to $2,000–$2,900 in avoided state tax — before compounding.

For tax-deferred accounts (IRAs, 401(k)s), the federal-state split is irrelevant. The instruments compete on yield, maturity, and execution. For taxable accounts, the tax efficiency is a structural advantage over corporate bonds and most municipal bond structures, since taxable munis carry federal liability and tax-exempt munis typically clear at lower yields.

We do not model individual tax scenarios. An investor in the 32%+ federal bracket will see a different after-tax yield than an investor in the 12% bracket, but the relative ranking between T-Bills and T-Notes does not change. If your horizon forces the choice, the tax treatment does not break the tie.

Execution Pathways: TreasuryDirect Versus Brokerage Platforms

T-Bills and T-Notes can be purchased directly from the U.S. government via TreasuryDirect, or through brokers, dealers, and banks. The execution channel affects cost, convenience, and operational risk.

TreasuryDirect is the no-fee direct channel. The platform supports both T-Bills (via the auction and the CUSIP-less secondary book) and T-Notes. Minimum purchase is $100, the same floor that applies at auction and through most brokers. The cost structure is the cleanest available: no commission, no markup, no bid-ask spread on primary auction purchases. Settlement occurs on the standard T+1 cycle for Treasuries, and TreasuryDirect funds purchases via ACH debit from a linked bank account. The ACH leg introduces a one-to-two-day funding lag, which means the cash must be in the linked account before the auction closes.

Brokerage platforms add a layer. The cost is typically zero commission on U.S. Treasuries at major retail brokers, but the execution price may carry a small dealer markup on the secondary market. For large block purchases, institutional dealers negotiate tighter spreads. For retail-sized orders ($1,000 to $100,000), the difference between TreasuryDirect and a zero-commission brokerage is often negligible after accounting for TreasuryDirect's funding friction (ACH transfer timing, account funding limits).

The operational difference that matters: TreasuryDirect is the primary issuance channel and operates as a CUSIP-less book-entry system. Sales before maturity on TreasuryDirect are conducted via its secondary-sale mechanism, which is less liquid than the inter-dealer market. If you anticipate needing to exit before maturity, a brokerage account with access to the secondary market typically delivers tighter execution.

Settlement mechanics differ across platforms. TreasuryDirect settles on the auction date and debits the linked bank account via ACH — a process that takes one to two business days and requires the funds to be available before the auction closes. Brokerage accounts settle trades on T+1, the same cycle that applies to all Treasury transactions, but the funding is handled within the brokerage's margin and cash-management infrastructure. For investors managing multiple Treasury positions across maturities, the brokerage platform consolidates holdings, simplifies position tracking, and provides real-time pricing on secondary-market trades. TreasuryDirect, by contrast, is a single-purpose platform with limited portfolio visibility and no real-time market data.

One consideration for investors building a T-Bill ladder: the rollover frequency (every 4, 13, or 26 weeks) multiplies the number of settlement events. Each rollover is a new purchase, each with its own funding requirement. On TreasuryDirect, that means recurring ACH debits. On a brokerage platform, that means recurring cash availability checks. The friction is small on any single transaction, but it accumulates over a year of active ladder management. We treat operational simplicity as a secondary factor — it does not override the maturity and duration tests — but it is worth noting when the two execution paths are otherwise equivalent on cost.

Verdict

We run two tests. Test 1: does the maturity match the cash horizon? Test 2: will the position be held to maturity, or is the exit date uncertain?

Match the maturity to the liability. Match the exit probability to the duration. Do not buy a T-Note for short-term cash. Do not ladder T-Bills across a 5-year liability.

The instruments are tools, not yield products. T-Bills handle the sub-12-month layer of the cash stack with minimal duration drag and clean roll mechanics. T-Notes handle the 2-to-10-year layer with predictable coupon income and locked-in rates, provided the position survives to maturity. Anything outside those two operating envelopes — T-Bills stretched into multi-year liabilities, T-Notes sold before term in a rising-rate environment — is a structural mismatch, and the data will show it. Select by horizon, not by headline yield.