CDs vs Treasury Bonds: Where to Park Short-Term Cash for Better Returns

As of April 2025, the U.S. Federal Reserve has held the federal funds rate at 5.25%-5.50% since July 2023, the highest level in 22 years, according to the Federal Reserve’s Federal Open Market Committee (FOMC) press release. This elevated rate environment has created a rare opportunity for short-term cash savers: both Certificates of Deposit (CDs) and Treasury bonds are offering annual percentage yields (APYs) above 5%. For example, a 6-month CD from a top online bank currently yields around 5.30% APY, while a 6-month Treasury bill (T-bill) is yielding approximately 5.35% at auction, per the U.S. Department of the Treasury’s daily yield curve data. However, the choice between these two instruments is not purely about the headline rate. State tax treatment, liquidity, and FDIC vs. government backing differ significantly. For international residents or newcomers to the U.S. financial system, understanding these differences can mean the difference of hundreds of dollars in net return on a $50,000 cash position over a six-month period. This guide breaks down the key factors—yield, tax, risk, and accessibility—so you can decide where to park short-term cash for better after-tax returns.

Yield Comparison: Which Pays More Right Now?

The most direct comparison is the annualized yield. As of late April 2025, short-term Treasury bills (3-month, 6-month, 1-year) are auctioning at yields between 5.20% and 5.40%, according to the U.S. Treasury’s daily yield curve. Meanwhile, high-yield CDs from online banks (e.g., Ally Bank, Marcus by Goldman Sachs) offer 5.00% to 5.30% APY for comparable terms.

Key difference: compounding. CD yields are typically quoted as APY (Annual Percentage Yield), which assumes interest is compounded monthly or quarterly. Treasury yields are quoted as yield-to-maturity on a discount basis (you buy at a discount and receive face value at maturity). For a 6-month term, the difference is negligible—roughly 0.05-0.15 percentage points in favor of T-bills at current auction rates. However, if you plan to sell before maturity, T-bills have a secondary market with price risk, while CDs (especially no-penalty CDs) offer more predictable early-exit terms.

Brokered CDs vs. Bank CDs

If you buy CDs through a brokerage account (e.g., Fidelity, Schwab), you may see brokered CDs offering higher yields than bank-issued CDs. These are still FDIC-insured but can be traded on secondary markets. Current brokered 6-month CD yields hover around 5.35%, nearly matching T-bills. However, brokered CDs may have call features—the bank can redeem them early if rates drop, forcing you to reinvest at lower rates. T-bills have no call risk.

Treasury Bill Auction Mechanics

T-bills are sold at weekly auctions. You can buy directly through TreasuryDirect.gov (non-competitive bidding) or through a brokerage. The yield is determined by the discount from face value. For example, a $10,000 6-month T-bill purchased at $9,750 yields $250 at maturity, a 5.13% annualized return. Non-competitive bidding guarantees you get the auction’s average yield, making it simple for retail investors.

Tax Treatment: The Hidden Decider for High-Income Earners

The most overlooked factor in the CD vs. Treasury decision is state and local income tax. Treasury interest is exempt from state and local taxes, while CD interest is fully taxable at all levels. For residents of high-tax states like California (13.3% top marginal rate), New York (10.9%), or Oregon (9.9%), this exemption can dramatically improve after-tax returns.

Example calculation: A $100,000 investment in a 6-month CD at 5.30% APY yields $2,650 in interest. In California, a top-bracket earner pays 13.3% state tax + 37% federal (plus 3.8% Net Investment Income Tax) = roughly 54% total marginal rate. After tax, the CD yields about $1,219 net. A 6-month T-bill at 5.35% yield produces $2,675 interest, but only federal tax applies (37% + 3.8% = 40.8%), leaving $1,584 net. The T-bill generates $365 more after tax—a 30% improvement.

For residents of states with no income tax (Texas, Florida, Nevada, Washington, Wyoming, South Dakota, Alaska), the tax advantage of Treasuries disappears, and CD yields may be slightly higher on a pre-tax basis.

Federal Tax Treatment of Both

Both CD interest and Treasury interest are subject to federal income tax. However, Treasury interest is exempt from state and local taxes, while CD interest is not. This is codified in 26 U.S. Code § 103 (for municipal bonds) and 31 U.S. Code § 3124 (for Treasury obligations). No special forms are needed—your brokerage or bank will issue a 1099-INT or 1099-OID.

Impact on Foreign Nationals (Non-Resident Aliens)

Non-resident aliens (NRAs) are generally exempt from U.S. capital gains tax but are subject to 30% withholding on interest income from U.S. sources (unless reduced by a tax treaty). However, Treasury interest is often exempt from this withholding under the “portfolio interest” exception (26 U.S. Code § 871(h)). CD interest does not qualify for this exception. Therefore, for NRAs holding short-term cash in U.S. accounts, T-bills may be significantly more favorable—avoiding both state tax and the 30% withholding. Consult IRS Publication 519 for your specific country treaty.

Risk and Insurance: FDIC vs. Full Faith and Credit

Both CDs and Treasuries are considered extremely safe, but the nature of their guarantees differs. CDs are insured by the Federal Deposit Insurance Corporation (FDIC) up to $250,000 per depositor, per bank. Treasuries are backed by the “full faith and credit” of the U.S. government, meaning default risk is effectively zero—the U.S. has never defaulted on its debt obligations.

For amounts under $250,000, the risk difference is academic—both are essentially risk-free. For amounts above $250,000, Treasuries offer unlimited safety (the government can print money to pay), while CDs require splitting across multiple banks to maintain FDIC coverage. A $500,000 cash position would need two separate bank accounts for full FDIC coverage, whereas a single $500,000 T-bill purchase carries no insurance limit concern.

Liquidity risk: T-bills can be sold on the secondary market before maturity, but you may receive less than face value if rates have risen (price risk). CDs, especially traditional bank CDs, often have early withdrawal penalties (e.g., 3-6 months of interest). No-penalty CDs exist (yielding ~4.50% currently) but offer lower rates. For cash you truly need in 3-6 months, T-bills offer better liquidity with minimal price risk for short durations.

Inflation Risk for Both

Neither instrument protects against inflation. With CPI running at 3.5% year-over-year as of March 2025 (Bureau of Labor Statistics), a 5.30% CD or T-bill yields a real return of about 1.8%. For longer-term cash needs (2+ years), Treasury Inflation-Protected Securities (TIPS) or I Bonds may be more appropriate, but these are outside the short-term scope.

Accessibility and Minimums: How Easy Is It to Buy?

CDs are available at virtually every bank and credit union in the U.S. Minimum deposits range from $0 (online banks) to $1,000 (some traditional banks). You can open a CD online in minutes, and the interest rate is locked for the term. For international residents without a U.S. Social Security Number (SSN), opening a CD may be possible with an Individual Taxpayer Identification Number (ITIN) and a U.S. bank account, though not all banks accept ITINs.

Treasuries require a U.S. TreasuryDirect account (requires SSN or ITIN) or a brokerage account. Minimum purchase for T-bills via TreasuryDirect is $100. Buying through a brokerage (Fidelity, Schwab, Vanguard) is simpler for many—you can buy T-bills at auction or on the secondary market with no commission. For international residents, opening a U.S. brokerage account may require a U.S. address and SSN, though some brokerages accept non-resident applications.

For cross-border tuition payments or moving funds between countries, some international families use channels like Airwallex global account to settle fees and hold short-term cash across currencies.

Which One Should You Choose? A Decision Framework

The optimal choice depends on three variables: your state tax rate, your cash amount, and your need for flexibility.

• Choose T-bills if: You live in a high-tax state (CA, NY, OR, MN, HI, NJ, CT, MA, VT, DC) OR you are a non-resident alien OR you hold more than $250,000 in cash. The state tax exemption and unlimited government backing make T-bills the clear winner.
• Choose CDs if: You live in a no-income-tax state (TX, FL, NV, WA, WY, SD, AK, TN, NH) OR you want a fixed rate with no auction complexity OR you prefer FDIC insurance for psychological comfort. CDs from online banks often offer slightly higher advertised APYs than T-bills when state tax is not a factor.
• Choose a mix if: You have a large cash position. For example, put $250,000 in a CD (FDIC-covered) and the rest in T-bills. Or ladder: buy 3-month, 6-month, and 9-month T-bills to create a rolling maturity schedule.

Practical tip: Compare the after-tax yield using this formula: After-tax yield = Pre-tax yield × (1 - federal marginal rate - state marginal rate) for CDs; for T-bills, After-tax yield = Pre-tax yield × (1 - federal marginal rate). Use your actual marginal tax rates from your 2024 tax return.

FAQ

Q1: Are Treasury bills safer than CDs?

Yes and no. Both are among the safest investments available. CDs are insured by the FDIC up to $250,000 per depositor per bank—meaning if the bank fails, the U.S. government covers your loss up to that limit. Treasuries are backed by the full faith and credit of the U.S. government with no dollar limit. For amounts under $250,000, the safety is equivalent. For amounts over $250,000, Treasuries are safer because there is no insurance cap. Historically, the U.S. government has never defaulted on its debt, while over 500 banks have failed since 2000 (FDIC data, 2024).

Q2: Can I lose money on a CD or Treasury bill if I hold to maturity?

No, you cannot lose principal if you hold either instrument to maturity, assuming the bank does not fail (for CDs) or the U.S. government does not default (for Treasuries). If you sell before maturity, you could lose money if interest rates have risen since purchase. For example, if you buy a 1-year CD at 5% and rates jump to 6%, selling the CD early may incur a penalty (typically 3-6 months of interest) or a discount on the secondary market. T-bills sold early on the secondary market may trade below your purchase price if rates have risen. However, holding to maturity guarantees you receive full face value.

Q3: What is the minimum amount needed to buy a Treasury bill?

The minimum purchase for a Treasury bill through TreasuryDirect.gov is $100. Through a brokerage (Fidelity, Schwab, Vanguard), the minimum is typically $1,000 for new issues at auction. For secondary market T-bills, minimums vary by broker but are often $1,000. In comparison, CDs from online banks often have no minimum deposit (e.g., Ally Bank, Marcus). For small cash amounts (under $1,000), a CD may be more accessible. For amounts over $10,000, T-bills are equally easy to purchase through any brokerage account.

References

• Federal Reserve, Federal Open Market Committee (FOMC) Press Release, March 2025
• U.S. Department of the Treasury, Daily Treasury Par Yield Curve Rates, April 2025
• Federal Deposit Insurance Corporation (FDIC), Quarterly Banking Profile, Q4 2024
• Bureau of Labor Statistics, Consumer Price Index (CPI) March 2025 Report
• Internal Revenue Service, Publication 519 (U.S. Tax Guide for Aliens), 2024