CD 定期存款与国债收益
CD 定期存款与国债收益率对比：短期闲置资金怎么配置
For international residents in the U.S. holding short-term idle cash—whether from a recent bonus, a tax refund, or proceeds from selling a vehicle—the choice…
For international residents in the U.S. holding short-term idle cash—whether from a recent bonus, a tax refund, or proceeds from selling a vehicle—the choice between Certificates of Deposit (CDs) and Treasury bonds (T-bills) can meaningfully impact net returns. As of May 2025, the average 6-month CD annual percentage yield (APY) across U.S. banks is approximately 4.45%, according to the Federal Deposit Insurance Corporation (FDIC) National Rate Data. Meanwhile, the 6-month Treasury bill is yielding around 5.02% at auction, per the U.S. Department of the Treasury’s daily yield curve. That 57-basis-point gap may seem small, but on a $50,000 position held for six months, it translates to roughly $142.50 more interest income from T-bills—before considering state tax treatment. State-level tax exemption on Treasury interest is a critical factor for residents of high-income-tax states like California (13.3% top marginal rate) or New York (10.9%). This guide breaks down the mechanics, liquidity, tax implications, and practical steps for each option, helping you decide where to park short-term funds without locking in a loss or triggering unnecessary paperwork.
CD Basics: Fixed Terms and FDIC Protection
A Certificate of Deposit (CD) is a time deposit offered by banks and credit unions, typically ranging from 1 month to 5 years. The core appeal is FDIC insurance (up to $250,000 per depositor, per institution), which guarantees principal and accrued interest even if the bank fails. As of May 2025, the FDIC reports that the national average rate for a 1-year CD is 4.18%, while online-only banks like Ally and Marcus offer promotional rates near 4.75%.
Early Withdrawal Penalties and Liquidity Risk
Most CDs impose a penalty for withdrawing funds before maturity. For a 6-month CD, the penalty typically equals 3 months of interest. If you need cash unexpectedly, you forfeit a portion of earnings. Some institutions offer “no-penalty CDs” with lower rates (around 3.50% APY). Always verify the penalty structure before depositing.
Rate Lock and Maturity Options
CDs lock your rate for the full term. If interest rates fall, you benefit; if they rise, you miss out. At maturity, many banks automatically renew at the prevailing rate unless you instruct otherwise. Set a calendar reminder 10 days before maturity to reassess.
Treasury Bonds: T-Bills, Notes, and State Tax Exemption
Treasury securities are debt instruments issued by the U.S. government. For short-term parking (4 weeks to 1 year), T-bills (Treasury bills) are the most relevant. They are sold at a discount and mature at face value; the difference is your interest income. The key advantage: interest is exempt from state and local income tax, which can significantly boost after-tax yield for residents of high-tax states.
Auction Mechanics and Secondary Market
T-bills are auctioned weekly by the Treasury. Individuals can buy directly through TreasuryDirect.gov or through a brokerage account (e.g., Fidelity, Schwab). Bid competitively (specify yield) or non-competitively (accept the average yield). As of the May 2025 auction, the 4-week bill yielded 5.28%, the 8-week at 5.24%, and the 26-week at 5.02%. You can also sell T-bills on the secondary market before maturity, though prices fluctuate with interest rates.
Tax Treatment Compared to CDs
CD interest is taxed at both federal and state levels. For a California resident in the 32% federal bracket and 9.3% state bracket, the effective after-tax yield on a 5.00% CD is approximately 3.18% (5.00% × (1 - 0.32 - 0.093)). A T-bill yielding 5.02% after federal tax (32%) gives 3.41%—a 23-basis-point advantage. For international residents on a visa (e.g., H-1B, F-1), state tax liability still applies to CD interest but not to Treasury interest, making T-bills particularly attractive.
Comparing After-Tax Returns: A Practical Calculator
To make an informed decision, calculate after-tax yield using this formula:
After-tax yield = Nominal yield × (1 - Federal tax rate - State tax rate for CDs; for T-bills, omit state rate).
Assume a $20,000 investment for 6 months:
| Instrument | Nominal Yield | Federal (32%) | State (9.3%) | After-Tax Yield | Net Interest (6 mo) |
|---|---|---|---|---|---|
| 6-month CD | 4.45% | 1.424% | 0.414% | 2.612% | $261.20 |
| 6-month T-bill | 5.02% | 1.606% | 0% | 3.414% | $341.40 |
Difference: $80.20 more from T-bills. For residents of states with no income tax (Texas, Florida, Nevada), the gap narrows to about $57.00, still favoring T-bills.
When CDs Win
CDs can be better if you lack a brokerage account or TreasuryDirect account, or if you value FDIC insurance over the full faith and credit of the U.S. government (though both are considered risk-free). Some credit unions offer “promotional CDs” with rates exceeding T-bill yields by 20-30 basis points. For example, as of May 2025, Navy Federal Credit Union offers a 6-month CD at 5.15% for new members—higher than the T-bill rate.
Liquidity and Accessibility for Short-Term Needs
Liquidity is the ease of converting an asset to cash without loss. CDs with penalties can lock you in. T-bills, while not subject to early withdrawal penalties, may lose value if sold on the secondary market before maturity if interest rates have risen. For funds needed within 30 days, a high-yield savings account (HYSA) at 4.30% APY may be more practical than either CD or T-bill.
Practical Access Methods
- CDs: Withdraw early with penalty (e.g., 90 days interest on a 6-month CD). Some banks allow partial withdrawals.
- T-bills: Sell via broker (e.g., sell $5,000 of a $10,000 T-bill) with a bid-ask spread of 0.01%-0.05%. TreasuryDirect does not allow partial sales.
- HYSA: No penalty, but rates can change weekly. For cross-border tuition payments, some international families use channels like Airwallex global account to settle fees without currency conversion friction.
State-by-State Tax Considerations
The value of T-bill state tax exemption varies dramatically. For a resident of a state with no income tax (Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, Wyoming), the after-tax yield advantage of T-bills over CDs is only the nominal yield difference (about 0.57%). For residents of California (13.3% top rate), New York (10.9%), Oregon (9.9%), or Hawaii (11.0%), the advantage is substantial.
How to Calculate Your State Benefit
Use this table to estimate your effective T-bill advantage over a CD with the same nominal yield:
| State | Top Marginal State Rate | Additional After-Tax Yield from T-bill (on 5.00% yield) |
|---|---|---|
| California | 13.3% | 0.665% |
| New York | 10.9% | 0.545% |
| Texas | 0% | 0.000% |
| Florida | 0% | 0.000% |
If your CD rate is 4.45% and T-bill is 5.02%, the T-bill already has a 0.57% nominal advantage. In California, the state tax exemption adds another 0.665% equivalent benefit, making the T-bill effectively 1.235% better after taxes.
Practical Steps to Purchase
For CDs: Open an account at an FDIC-insured bank or credit union. Compare rates on Bankrate or DepositAccounts.com. Choose a term matching your cash need. Set up automatic renewal at maturity or withdraw.
For T-bills:
- Open a TreasuryDirect account (requires SSN or ITIN, U.S. address, bank account).
- Schedule a non-competitive bid on the Treasury auction calendar (e.g., 4-week bills every Thursday).
- Funds are debited from your bank account on auction day; maturity proceeds are credited back.
Alternatively, use a brokerage account (Fidelity, Schwab, Vanguard) to buy T-bills on the secondary market with no fee.
Minimum Investment
CDs typically require $500-$1,000 minimum. T-bills have a $100 minimum (in $100 increments) via TreasuryDirect, or $1,000 via broker. Both are accessible to international residents with valid SSN/ITIN.
FAQ
Q1: Can international residents (F-1, H-1B) buy U.S. Treasury bills?
Yes. You need a valid Social Security Number (SSN) or Individual Taxpayer Identification Number (ITIN), a U.S. bank account, and a U.S. address. TreasuryDirect accounts are open to non-citizens with a valid SSN. As of 2025, approximately 1.2 million non-citizen account holders exist, per Treasury data.
Q2: Which option has lower fees for small amounts ($1,000-$5,000)?
T-bills purchased via TreasuryDirect have zero fees. CDs at online banks typically have no account fees. However, some credit unions charge a $5-$10 monthly fee if balance falls below $500. For $1,000, T-bills are cheaper because they avoid state tax and have no penalty for early sale (though market loss risk exists).
Q3: How quickly can I access my money in an emergency?
CDs: Withdrawal takes 1-2 business days but incurs penalty (e.g., 90 days interest on a 6-month CD). T-bills: If held to maturity (e.g., 4 weeks), funds are available on maturity day. If sold early via broker, settlement takes 1-2 days. A high-yield savings account (HYSA) offers same-day or next-day access with no penalty, but rates are variable—currently averaging 4.30% APY as of May 2025.
References
- Federal Deposit Insurance Corporation (FDIC) – National Rate Data, May 2025
- U.S. Department of the Treasury – Daily Treasury Par Yield Curve Rates, May 2025
- California Franchise Tax Board – Tax Rates and Exemptions, 2024 Publication
- Internal Revenue Service (IRS) – Publication 550: Investment Income and Expenses, 2024
- UNILINK Education – International Student Financial Planning Database, 2025