Updated: August 30, 2026
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A retiree holding a maturing bank CD in 2026 has a landscape decision to make inside a narrow grace window. As of September 2026, FDIC national-average CD rates published August 17, 2026 sit well below recent US Treasury bill auction results. That gap is why the T-bill route now enters the conversation for CD depositors who never previously bought government paper directly.
This page compares Treasury bills and bank CDs on the specific mechanics that determine which instrument fits which situation. It is a landscape map of the two products, not a product recommendation. Every number cited is dated to its source, and the account agreement or TreasuryDirect help center is always the source of truth on the specific detail.
How each instrument is bought
A bank certificate of deposit is opened at a bank or credit union. The channels are the branch counter, the phone deposit-services line, and the online-banking account view. The depositor selects a term, funds the CD from a linked checking or savings account, and signs the truth-in-savings disclosure that lays out the rate, term, and early-withdrawal penalty.
A Treasury bill is bought at the source through a free TreasuryDirect account or through a brokerage account. TreasuryDirect is the retail purchase channel operated by the US Department of the Treasury. Bills there are bought at auction as a non-competitive bid, which means the buyer accepts the rate set by the auction result and is guaranteed the requested amount.
A brokerage account offers an alternative route. Fidelity, Schwab, Vanguard, and other retail brokers let clients buy Treasury bills at auction or on the secondary market inside the same account that holds their other securities. The trade-off is broker involvement in custody and reporting instead of a direct account with the Treasury.
Term structures side by side
Bank CDs are offered across a broad range of terms. National banks and credit unions typically list 3-month, 6-month, 12-month, 24-month, 36-month, 48-month, and 60-month CDs. Some institutions extend the ladder to 84 months or 10 years. The available terms and the posted rates vary from institution to institution.
Treasury bills are issued in a fixed set of short maturities: 4, 6, 8, 13, 17, 26, and 52 weeks. The 4, 6, 8, 13, 17, and 26-week bills are auctioned weekly. The 52-week bill is auctioned every four weeks. There is no T-bill product beyond one year; longer government maturities are issued as Treasury notes or bonds.
The shape of the choice at CD maturity is clear. Anything the depositor wants to lock beyond one year fits the CD product set only. Anything up to one year can be filled by either instrument, with the T-bill covering weeks-to-months buckets that most banks do not offer at all.
Yield mechanics: APY versus discount
A CD posts an annual percentage yield. The APY is a compounding-adjusted figure disclosed under the federal Truth in Savings rules. The bank credits interest to the CD at the disclosed frequency, and the depositor receives principal plus accumulated interest at maturity.
A T-bill is sold at a discount to face value. The buyer pays less than the face amount at issue and receives the full face value at maturity. The difference is the interest. The TreasuryDirect pricing page publishes the formula: price equals face value multiplied by one minus the discount rate times days-to-maturity divided by 360.
Treasury auction results report two figures. The high discount rate is the auction-clearing yield used to price the bill. The investment rate is the same yield expressed on an annualized basis comparable to a bond-equivalent yield. When comparing a T-bill to a CD APY, the investment rate is the like-for-like figure to use.
The safety mechanism
A bank CD is a deposit product covered by FDIC insurance up to $250,000 per depositor, per insured bank, per ownership category. Coverage is automatic when the CD is opened at an FDIC-insured institution. Depositors above the $250,000 ceiling can spread balances across banks or ownership categories to preserve full insurance.
A Treasury bill is a direct obligation of the US federal government. The FDIC does not insure T-bills; instead the bill is backed by the full faith and credit of the United States. There is no dollar cap on this backing. A one-million-dollar T-bill position carries the same government backing as a one-hundred-dollar T-bill position.
The two protections cover different risks. FDIC insurance protects the depositor if a specific bank fails. Full faith and credit backing protects the T-bill holder if the Treasury itself defaults on interest or principal, an event outside the historical experience of the US bond market. Neither protection covers market-price risk on a bill sold before maturity.
State and local tax: the structural gap
Interest on a bank CD is fully taxable federal income and is also included in state and local taxable income wherever the depositor lives. A depositor in a high-tax state loses a meaningful share of the coupon to state income tax on CD interest.
Interest on a Treasury bill is exempt from state and local income tax. The exemption is codified in 31 USC 3124(a), which states that stocks and obligations of the United States government are exempt from taxation by a State or political subdivision of a State. The exemption applies to any form of taxation that would require the interest to be included in a state tax calculation.
The practical effect scales with state income tax rate. A retiree in a state with a 5 percent income tax on interest keeps 5 percent more of the coupon on a T-bill than on a CD of the same pre-tax yield. In a no-income-tax state such as Florida or Texas, the state-tax advantage is nil.
Liquidity before maturity
A bank CD is a term deposit. Withdrawing before the term ends triggers the early-withdrawal penalty disclosed in the truth-in-savings paperwork. Typical penalty schedules run three months of interest for a 12-month CD, six months of interest for a 24-month CD, and up to twelve months of interest for longer terms.
A Treasury bill can be sold on the secondary market before maturity. The bill must be transferred out of TreasuryDirect to a brokerage account first, then sold at the market bid. There is no early-withdrawal penalty, but there is market-value risk: the bill sells at whatever price the market clears on the sale date.
For shorter T-bills, price volatility between issue and maturity is modest, and the market is deep. For CD holders who need funds mid-term, the penalty is a known, disclosed cost. For T-bill holders who need funds mid-term, the outcome depends on interest rate moves since purchase.
Auto-rollover mechanics
A bank CD auto-renews at the end of its grace period. Unless the depositor files an election inside the grace window, the balance rolls into a new CD of the same term at the bank’s currently posted rate. The rollover is silent, and the disclosed early-withdrawal penalty attaches to the new term.
A TreasuryDirect bill can be scheduled for reinvestment up to two years forward. Per TreasuryDirect help center guidance, bills may be scheduled for multiple reinvestments up to two years, whereas notes, bonds, and Floating Rate Notes can only be scheduled for one reinvestment each. The depositor sets the schedule when buying the bill or any time up to four business days before maturity.
The mechanisms differ in default behavior. A CD’s default is roll-forward at whatever rate the bank posts on the roll date. A T-bill’s default is settle the proceeds to the linked bank account or Certificate of Indebtedness, and only reinvest if a schedule was set. Neither default is right or wrong; the depositor needs to know which applies.
The three-month rate comparison, as of August 2026
The most useful comparison at CD maturity is the short-end yield spread. The chart below shows the FDIC national-average CD deposit rate against the recent TreasuryDirect auction investment rate at the closest comparable T-bill terms.
The gap in favor of the T-bill at each of these three buckets is meaningful. A depositor whose maturing CD auto-renews at the FDIC national-average 12-month rate of 1.71 percent locks in a coupon that is well below the recent 52-week T-bill auction result of 4.05 percent. Individual bank offers can price above or below the national average, and rates change with each release.
Inside an IRA: does the T-bill advantage disappear?
Both instruments are eligible IRA holdings. A bank IRA CD sits inside the IRA custodial account at the depositor’s bank. A T-bill sits inside a brokerage IRA account, since TreasuryDirect does not offer a retirement account wrapper for individuals.
The state-tax advantage of the T-bill is neutralized inside an IRA. The IRA is already a tax-deferred wrapper, so no interest is reported on the depositor’s current-year state return regardless of the underlying instrument. A T-bill held in an IRA offers the same rate advantage as a taxable T-bill, but the tax angle for the comparison collapses.
Moving a maturing IRA CD into a brokerage IRA that holds T-bills is a trustee-to-trustee transfer, not a distribution. The IRS treats trustee-to-trustee transfers between IRA custodians as non-taxable and non-reportable events, per Publication 590-A. The 60-day rule and the once-per-year rollover limit do not apply.
The maturing-CD refugee scenario
The narrow scenario driving traffic to this comparison is the depositor whose CD was opened at the 2024 rate peak and is now maturing into a lower-rate environment. Inside the bank’s grace window, the depositor has to choose between the auto-renewal at the bank’s currently posted rate and any other option.
Rolling the maturing balance into a 13-week or a 26-week Treasury bill offers two features simultaneously. The T-bill investment rate has recently priced above the FDIC national-average short-term CD rate, and the shorter maturity keeps the balance liquid enough to be redeployed once the rate landscape resettles. This is the case where the T-bill route earns its consideration for a CD depositor.
The trade-off is operational. The depositor has to open a TreasuryDirect account or route the purchase through an existing brokerage account, learn the auction schedule, and set up reinvestment or manual redeployment at maturity. For depositors who value the branch relationship and the deposit-account simplicity, the incremental yield may not be worth the process change.
Side-by-side comparison
| Feature | Bank CD | Treasury bill |
|---|---|---|
| Where bought | Bank branch or online banking | TreasuryDirect account or brokerage account |
| Available terms | 3 months to 10 years, per institution | 4, 6, 8, 13, 17, 26, 52 weeks |
| Minimum purchase | Often $500 to $1,000, per institution | $100, in $100 increments |
| Yield presentation | Annual percentage yield (APY) | Discount rate + investment rate |
| Interest payment | At disclosed frequency, credited to CD | At maturity, as the discount-to-par gap |
| Safety mechanism | FDIC insurance up to $250,000 per depositor per insured bank | Full faith and credit of the US Treasury, no dollar cap |
| Federal income tax | Interest taxable federal | Interest taxable federal |
| State and local income tax | Interest taxable state and local | Interest exempt under 31 USC 3124(a) |
| Early liquidity | Early-withdrawal penalty per truth-in-savings disclosure | Sell on secondary market via brokerage, subject to market price |
| Auto-rollover | Auto-renew at bank’s currently posted rate after grace period | Scheduled reinvestments up to two years forward, per TreasuryDirect help center |
| IRA compatibility | Yes, bank IRA CD | Yes, brokerage IRA holding T-bills |
| State-tax advantage inside an IRA | N/A, IRA is tax-deferred | Neutralized, IRA is already tax-deferred |
The educational reminder
This page describes industry-standard mechanics for bank certificates of deposit and US Treasury bills. It does not describe the specific terms of any one CD, the exact posted rate at any one bank, or the auction result on any specific future date.
The account agreement for the CD in question and the TreasuryDirect help center are the enforceable and current sources of truth on the details. Confirm the CD’s grace-period length and early-withdrawal penalty schedule before the maturity date. Confirm the TreasuryDirect account funding steps and auction calendar before submitting a first non-competitive bid.
Nothing on this page is investment, tax, or legal advice. A depositor with a large maturing balance, complex state tax situation, or IRA transfer paperwork should consult a licensed adviser before moving funds. The how OPRS vets outside custodians page covers the general framework for vetting a receiving institution when a transfer moves the balance to a new custodian.
Sources cited
- US Department of the Treasury, TreasuryDirect, Treasury Bills, the official landing describing bill maturities, purchase minimum, auction frequency, and discount-to-par pricing mechanics.
- US Department of the Treasury, TreasuryDirect, Help Center, the official help hub covering account opening, reinvestment scheduling, and secondary-market transfer procedures for individual investors.
- Federal Deposit Insurance Corporation, Are My Deposit Accounts Insured by the FDIC, the FDIC page covering coverage of certificates of deposit and the $250,000 per depositor per insured bank per ownership category standard.
- Cornell Legal Information Institute, 31 U.S. Code Section 3124, the statutory exemption of United States government obligations from taxation by a State or political subdivision of a State.
- Federal Deposit Insurance Corporation, National Rates and Rate Caps, the monthly FDIC release of national deposit rates and rate caps for insured US depository institutions across CD terms.