Last updated: May 17, 2026
🏦 CD vs Treasury Bills: Where to Park Cash?
📊 Side-by-Side Comparison
| Aspect | CD (Certificate of Deposit) | Treasury Bills (T-Bills) |
|---|---|---|
| Issuer | FDIC-insured bank. | US Treasury (full faith and credit). |
| Yield (1-yr, 2026) | 4.5-4.85% APY top online CDs. | 4.7-5.0% bond-equivalent yield. |
| State Tax | Fully taxable in state of residence. | State-tax EXEMPT (federal only). |
| Insurance/Backing | FDIC up to $250K per bank/depositor. | No cap — Treasury backing. |
| Liquidity | Locked. Early withdrawal = 3-6 months interest penalty. | Sell on secondary market anytime (small price risk). |
| Minimum | $500-$5,000 typical. | $100 (via TreasuryDirect). |
| Bottom Line | Simpler, bank-rewarded, capped at $250K protection. | Better after-tax yield + true liquidity + no cap. |
What is CD (Certificate of Deposit)?
A Certificate of Deposit (CD) is a time-locked deposit at a bank where you commit funds for a fixed term (3 months to 5 years) in exchange for a fixed interest rate. The bank pays interest monthly, quarterly, or at maturity, and the principal returns to you on the maturity date. FDIC insurance protects deposits up to $250,000 per depositor per bank per account category — meaning your money is safe even if the bank fails.
In 2026, top online banks (Ally, Marcus, Discover, Synchrony) offer 1-year CDs at 4.5-4.85% APY, with 18-month and 5-year terms running 4.0-4.5%. Brick-and-mortar bank CDs typically pay much less (0.5-2.0%). The CD's biggest weakness: early withdrawal triggers a penalty of 3-6 months of interest, sometimes more for longer-term CDs. This makes CDs inappropriate for funds you might need before maturity.
→ Try our Savings Goal Calculator
What is Treasury Bills (T-Bills)?
Treasury Bills (T-Bills) are short-term US government debt issued in maturities of 4, 8, 13, 17, 26, and 52 weeks. You buy them at a discount (e.g., $9,875 for a 13-week bill) and receive face value at maturity ($10,000). The difference is your interest. Yields are quoted as bond-equivalent yields and in 2026 run 4.7-5.0% for 13-26 week bills — slightly above CD rates.
T-Bills have three structural advantages over CDs: (1) the interest is exempt from state and local income tax — meaningful in high-tax states like California (13.3%), New York (10.9%), or Hawaii (11%), (2) backed by the US Treasury rather than a bank, with no $250K cap, (3) truly liquid via TreasuryDirect or any brokerage — you can sell anytime on the secondary market with minimal price impact for short-term bills. Buying via TreasuryDirect.gov has zero fees; buying via Fidelity, Schwab, or Vanguard also has $0 commission on new-issue Treasuries.
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🔑 Key Differences
- Tax treatment: T-Bill interest is state-tax-exempt; CD interest is fully taxable.
- Backing: CD = FDIC $250K cap. T-Bill = Treasury full backing, no cap.
- Liquidity: CD = locked with penalty. T-Bill = sell anytime, small price impact.
- Yield 2026: T-Bills usually 10-25 bps higher than top CDs on similar terms.
- Minimum investment: CD $500-$5K typical. T-Bill $100 (very accessible).
- Reinvestment: CD auto-renews (often at lower rate). T-Bill matures to cash; you pick next move.
- Trade-off: CDs offer simpler 'set it and forget it' UX. T-Bills require auctions/secondary trades but reward you for the effort.
When to Use CD (Certificate of Deposit)
- You value simplicity and have $25K or less in one bank.
- You won't need the money before maturity (no penalty risk).
- Your state has no income tax (FL, TX, WA, NV, etc. — T-Bill tax advantage disappears).
- Your bank offers loyalty CD rate bumps or relationship perks.
When to Use Treasury Bills (T-Bills)
- You live in a high-tax state (CA, NY, NJ, MA, OR, MN, etc.) — state-tax exemption alone adds ~0.5%/yr after-tax yield.
- You have more than $250K to park (CDs require multiple banks; T-Bills have no cap).
- You want true liquidity (sell anytime without penalty).
- You want the simplest credit risk profile (Treasury beats FDIC).
⚖️ Pros and Cons
✅ CD (Certificate of Deposit) — Pros
- Simple and familiar
- Fixed rate guaranteed
- FDIC-insured up to $250K
- Bank relationship rewards
❌ Cons
- Locked with early-withdrawal penalty
- State-taxable everywhere
- $250K FDIC cap per bank
- Auto-renewal often at worse rate
✅ Treasury Bills (T-Bills) — Pros
- State-tax exempt (federal only)
- No insurance cap — Treasury backing
- Truly liquid (sell anytime)
- $100 minimum, very accessible
❌ Cons
- Slightly more complex to buy
- Yields fluctuate with auctions
- Price risk if sold before maturity (small for short bills)
- TreasuryDirect UX is dated
💡 Real-World Examples
Example 1: $25,000 for 1 Year in California (13.3% state tax)
CD at 4.7% APY: $1,175 gross interest. After CA tax: $1,175 − $156 (state) − $258 (federal 22%) = $761 net. T-Bill at 4.85%: $1,213 gross. After tax (federal only): $1,213 − $267 (22%) = $946 net. T-Bill wins by $185 (24% more after-tax).
Example 2: $300,000 in Florida (No State Tax)
CD: would need 2 banks (FDIC $250K cap). 2 × $150K CDs at 4.7% = $14,100 interest. T-Bills: single account, $300K × 4.85% = $14,550 interest. Both fully taxable federally. T-Bills win by $450 plus simpler single-account management.
Example 3: Emergency Fund — $40K
CD: locked for 1 year, penalty if you need money. 26-week T-Bills: roll over twice/yr, sell anytime if emergency hits, lose only a few weeks of interest. T-Bills better for emergency-adjacent funds you might tap.
❓ Frequently Asked Questions
How do I buy T-Bills?
Two ways: (1) TreasuryDirect.gov — free, direct from government, accept auction yield. (2) Brokerage (Fidelity/Schwab/Vanguard) — $0 commission on new-issue Treasuries, can also buy on secondary market. Brokerage gives better UX and easier integration with other investments.
Are T-Bills really safer than CDs?
Marginally yes. CDs are FDIC-insured (US government program). T-Bills are direct Treasury obligations — one fewer institutional intermediary. Both fail only if the US government fails. Functionally equivalent safety; T-Bills have no $250K cap.
What happens if interest rates rise after I buy a CD/T-Bill?
CD: locked at lower rate; consider 'breaking' the CD (pay early-withdrawal penalty) only if rate difference × remaining term > penalty cost. T-Bill: sell on secondary market — price will be slightly lower (rate up = price down), but you can immediately reinvest at higher new rate.
Is there a 1099-INT for both?
Yes. Bank sends 1099-INT for CD interest. TreasuryDirect sends 1099-INT for T-Bill interest (federal only). Brokerages also issue 1099-INTs. The form structure is identical.
Can I buy CDs and T-Bills in an IRA?
Yes for both. Inside an IRA, the state-tax advantage of T-Bills becomes irrelevant (all earnings tax-deferred). CDs and T-Bills offer similar value inside an IRA — pick whichever has the higher current yield.
🧮 Related Calculators on CalcHub
Savings Goal Calculator
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Compound Interest
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Emergency Fund Calculator
Size your emergency fund; T-Bills better for emergency-adjacent.
Tax Calculator
Estimate state-tax savings from holding T-Bills vs CDs.