Treasury Bills: A Smarter Place to Park Your Cash

Treasury bills are short-term debt securities issued by the US Department of the Treasury. Unlike bonds that pay periodic interest, T-bills are sold at a discount to their face value and mature at par — the difference is your return.

They come in six maturities: 4 weeks, 8 weeks, 13 weeks (3 months), 17 weeks, 26 weeks (6 months), and 52 weeks (1 year). The Treasury auctions new bills on a regular schedule, and they're backed by the full faith and credit of the United States government. That makes them effectively the safest investment on earth — safer than any bank deposit above the FDIC insurance limit. (For the longer-maturity Treasury family — notes, bonds, and TIPS — see How Treasury Bonds Work.)

A practical example: buy a 13-week T-bill with a face value of $10,000 at the current yield, you pay roughly $9,910 today. Thirteen weeks later, you receive $10,000. That $90 difference is your interest, and it works out to approximately 3.68% annualised.

As of April 30, 2026, the T-bill curve sits flat-and-low: 3-month at 3.68%, 6-month at 3.71%, 1-year at 3.72%. The Fed funds rate is 3.64% (mid-band, on hold since January). The 2-year Treasury yields 3.88%, and the 10-year is 4.40% — that ~70bp gap from 1-year to 10-year is the term premium, and it's wider than it was a month ago as long-end yields back up on stagflation worry.

The key comparison for most savers is T-bills versus high-yield savings accounts. Top HYSAs still advertise rates near 3.80%, but those rates are repricing lower every cycle — see the deep-dive on HYSA rates falling. Six months ago, many HYSAs offered 4.5% or more. T-bill yields are falling too — the 3M auction rate is down from 4.25% a year ago — but here's the critical difference: when you buy a T-bill, you lock in that rate for the full term. Your HYSA rate can drop tomorrow with no notice.

CDs offer similar rate-locking, but they typically charge early withdrawal penalties and they don't carry the state-tax exemption. A T-bill can be sold on the secondary market through a brokerage before maturity with no penalty — you'll receive the prevailing market price, which could be slightly more or less than what you paid depending on where rates have moved.

Nominal yield is what gets quoted. Real yield is what you keep after inflation. With March 2026 CPI running at 3.29% year-over-year (FRED CPIAUCSL: 330.293 vs 319.785 a year prior), the picture across the cash-equivalent universe looks much thinner than the headline rates suggest.

Here is the real-yield ladder for the cash-park decision, all anchored to today's inflation reading:

Two things jump out. First, every cash-equivalent option is barely positive in real terms. The era of free 4-5% real yields ended when the Fed pivoted in late 2025; we are now in the "keep up with inflation, plus a tip" zone. Second, the HYSA's apparent 0.12-pt advantage over the 1-year T-bill is not a free lunch — it's compensation for the variable-rate risk. If the Fed cuts another 25-50bp this cycle, top HYSAs will reprice within weeks while your 1-year T-bill keeps paying 3.72% locked.

The opportunity-cost framing flips the usual question. Instead of "which pays more today?" the better question is: what's the cost of being wrong about the next 12 months of rates? If you think Fed cuts are coming and HYSA promo rates will compress further, the 1-year T-bill is the cheaper insurance. If you think rates surprise to the upside, a 3-month rung lets you reload at higher yields without penalty.

For inflation-adjusted protection at the long end of this discussion, see I-Bonds vs Treasury Bonds — I-bonds re-rate with CPI every six months, but they lock you out for the first 12 months and cap purchases at $10,000 per person per year. They're a complement to T-bills, not a substitute.

Here's where T-bills pull ahead for tens of millions of Americans: interest from Treasury securities is exempt from state and local income tax. You only pay federal tax. A HYSA, money-market fund, and CD all get taxed at both levels.

That sounds like a minor detail. Run the numbers and it isn't. Take a saver with $50,000 in cash earning the current 3.68% T-bill yield — that's $1,840 of interest in year one. The state-tax-savings differential vs an equivalent-yielding HYSA looks like this for the top five US states by population:

For most middle-bracket savers, the realistic effective state rate is somewhere in the 4-9% range. On $50,000 cash, that's $74-$166 of tax saved per year — equivalent to picking up an extra 15 to 33 basis points of after-tax yield without changing instrument or taking any extra risk.

The two no-tax states (Texas, Florida — plus Alaska, Nevada, South Dakota, Tennessee, Washington, Wyoming) wash this advantage out. If you live there, the T-bill vs HYSA decision collapses to: rate-locking + sovereign credit, with no tax kicker. Still a real advantage in a falling-rate environment, but a smaller one.

For everyone else — and especially anyone in California, New York, New Jersey, Hawaii, Oregon, Minnesota, or DC — the math runs strongly in T-bills' favour the moment your cash position clears one to two months of expenses.

You have three main options, each with trade-offs.

TreasuryDirect.gov is the government's own platform. You can buy T-bills directly at auction with no fees or commissions. The minimum purchase is just $100. The interface is dated and the user experience is frankly poor, but it works. One serious limitation: you cannot easily sell before maturity through TreasuryDirect — you have to transfer holdings to a brokerage first, which adds friction.

Brokerage accounts at firms like Fidelity, Schwab, or Vanguard let you buy T-bills at auction or on the secondary market. Most charge no commission for Treasury purchases. The advantage here is flexibility — you can sell before maturity at the prevailing market price, manage T-bills alongside your other investments, and set up automatic reinvestment without the TreasuryDirect 2-year cap. For most people, this is the best option. The Treasury hub maps the full curve including longer-maturity notes and bonds for context.

T-bill ETFs like SGOV (iShares 0-3 Month Treasury Bond ETF) or BIL (SPDR Bloomberg 1-3 Month T-Bill ETF) give you T-bill exposure with the simplicity of buying a stock. You get daily liquidity and no need to manage maturities. The downside is a small expense ratio (SGOV charges 0.09% annually) and slightly less precise yield targeting. ETFs distribute interest as ordinary dividends, and the state-tax exemption generally still applies on the Treasury-derived portion — but your broker's 1099-DIV will break this out and your tax software needs the right state-by-state percentages to claim it. It's not automatic the way it is on a direct holding.

The single biggest objection to T-bills versus a savings account is operational friction. "I don't want to manage maturities. I just want my money to sit there and earn interest." Fair. Here's what the auto-roll machinery actually does on each platform — and what happens when you need to bail before maturity.

TreasuryDirect auto-reinvest. Set it once at purchase, and TreasuryDirect will automatically buy the same security at the next auction when the current one matures. The cap: up to 2 years of reinvestments from the original purchase date for bills. After that you have to set up a new auto-reinvest manually. This is the platform's main usability weakness — set-and-forget is set-and-remind-me-in-24-months.

Brokerage auto-roll. Fidelity, Schwab, and Vanguard each support auto-roll on Treasury auction purchases through their fixed-income desks. The mechanics differ slightly — Fidelity calls it "Auto Roll," Schwab uses "Auto Reinvest," Vanguard offers it through the Bond Desk — but functionally all three will redirect the maturity proceeds into the next equivalent-maturity auction without a 2-year cap. This is the cleanest set-and-forget experience available for direct T-bill ownership.

Secondary-market exit. This is what differentiates T-bills from CDs in a real liquidity squeeze. If you need cash before maturity, your brokerage can sell the bill at the current market price the same trading day. There's no early-withdrawal penalty — but you're price-takers in a real market, so if rates have risen since you bought, you'll receive less than face value (and potentially less than you paid). Practical bid-ask spreads on Treasury bills at major brokerages are typically a few basis points — small enough that an unplanned early exit costs you a fraction of one month's interest, not the multiple months a CD penalty would.

Tax timing nuance. T-bill discount accretion is reported on your 1099-INT in the year the bill matures, not the year you bought it. Buy a 52-week bill in October 2026 that matures in October 2027 and the entire interest figure shows up on your 2027 return. This is genuinely useful for year-end tax planning — you can shift interest into the following tax year by buying long bills late in the calendar year. (CDs, by contrast, accrue OID on a constructive-receipt basis if held more than 12 months. T-bills, being under 12 months, sidestep this entirely.)

Estate-planning footnote. Treasury securities held in a brokerage transfer normally with the rest of the account on death. TreasuryDirect-held bills require beneficiary designation through the platform itself, and the transfer process is notably more painful than the brokerage path. One more reason most savers should hold T-bills inside a brokerage, not directly at TreasuryDirect.

A T-bill ladder is a straightforward strategy: instead of putting all your cash into one maturity, you spread it across several. This gives you regular access to your money while capturing current rates across the curve. For longer-duration ladder construction, the Treasury bond ladder guide covers the same logic across notes and bonds.

A simple example with $40,000: $10,000 in 4-week bills, $10,000 in 13-week bills, $10,000 in 26-week bills, $10,000 in 52-week bills. Every few weeks a tranche matures, and you decide whether to spend the cash or reinvest at the prevailing rate.

This matters specifically right now. The Fed cut from 3.88% in November 2025 to 3.64% in January 2026, then held there through April 2026. Forward-looking FOMC commentary still leaves the door open to further easing if growth softens. A ladder strategy means your longer-dated 1-year T-bill keeps earning today's 3.72% locked even if the 3-month auction yield drops to 3.40% in October. Meanwhile, the shorter-dated rungs provide liquidity and the option to redirect cash if better opportunities (or higher rates) emerge.

Most brokerages will handle the auction-cycle mechanics for you. Set the auto-roll on each rung at purchase and the ladder maintains itself.

Each of these serves a purpose, and the right answer depends on your situation.

T-bills win on safety (direct US government obligation, not subject to FDIC limits), state-tax exemption, and rate-locking. They're ideal for amounts above the $250,000 FDIC insurance limit, for residents of high-tax states, and for anyone who wants to lock in today's 3.68-3.72% before further Fed cuts.

HYSAs win on simplicity and instant liquidity. There is no auction to wait for, no maturity to track, and no secondary market to navigate. If you need same-day access to your emergency fund, a HYSA is the right call. The trade-off is a variable rate that will keep falling.

CDs win on guaranteed rates over longer periods, occasionally with slightly higher headline yields than T-bills of the same maturity. But they come with early-withdrawal penalties (typically three to six months of interest), and the interest is fully taxable at the state level. A 12-month CD might beat a 52-week T-bill by 10-20bp before tax — only to lose that edge after state taxes for a California or New York saver.

The practical synthesis: keep one to two months of expenses in a HYSA for true emergencies. Move the rest of your cash reserves into a T-bill ladder. You get better after-tax returns, superior safety, and enough liquidity for any realistic need. For inflation-protected balance — separate from the cash bucket — see TIPS Explained.

T-bills are not exotic instruments. They are the simplest, safest securities the US government issues. But they make the most sense for specific profiles.

High-tax-state residents in California, New York, New Jersey, Hawaii, Oregon, and similar high-rate jurisdictions benefit most from the state-tax exemption. The higher your state tax rate, the wider the effective yield gap over HYSAs. A New York City resident in the top combined bracket gets roughly +33bp of after-tax pickup over an equivalent-yielding HYSA — material.

Emergency-fund overflow is a natural fit. Once you have immediate-access cash covered in a HYSA, additional reserves can earn more in T-bills without meaningfully sacrificing liquidity given brokerage secondary-market exit.

Short-term savings goals — a home down payment in six to twelve months, a tuition payment next semester, a planned large purchase — align well with T-bill maturities. You pick the maturity that matches your timeline and know within a basis point what you'll receive.

Savers with large cash positions above the $250,000 FDIC limit should consider T-bills seriously. There is no cap on Treasury holdings, the credit risk is effectively zero, and the after-tax pickup compounds.

Rate-sensitive savers who want to lock in current yields before further Fed cuts can use 26-week or 52-week bills to secure today's rates. With March CPI at 3.29% YoY (FRED 330.293), the Fed on hold at 3.64% since January, and forward markets pricing more easing into the second half of 2026, the rate path skews to the downside. Lock the 1-year now and you have at least one rung of the ladder paying 3.72% even if the 3-month auction yield falls to 3.40% by year-end.