For investors seeking passive income, the 2025 US Treasury market presents a clear divergence: short-duration bills (3-6 months) at 3.75-3.78% fail to outpace projected inflation, delivering negative real returns as low as -1.73%. Conversely, intermediate-duration inflation-protected securities offer the most compelling value. The 10-Year Treasury Inflation-Protected Security (TIPS) provides a guaranteed 1.81% real yield above the Consumer Price Index, making it the superior instrument for genuine capital preservation. Series I Bonds, with a 4.03% composite rate, offer robust inflation hedging but require a one-year holding period, a critical liquidity constraint for some portfolios.
Yield Curve & After-Tax Return Analysis
As of November 2025, the Treasury yield curve is notably flat, with the 10-year to 2-year spread at a modest 0.55%. This environment, shaped by expectations of Federal Reserve rate cuts into 2026, penalizes investors holding cash-equivalent instruments. With core PCE inflation at 2.9%, any nominal yield below this threshold erodes purchasing power. The data reveals that only securities with maturities of one year or longer generate a positive real return, a crucial distinction for wealth accumulation.
Analyzing a $50,000 investment over a one-year holding period quantifies this divergence. While longer-duration nominal bonds provide higher gross income, TIPS deliver superior after-tax returns for high-income investors due to the tax treatment of inflation adjustments. An investor in the 37% federal tax bracket nets $1,764 from 10-Year TIPS versus just $1,291 from a 10-Year T-Bond, a 36.6% increase in take-home income. The most significant structural advantage for US investors, however, is the state and local tax (SALT) exemption. For a California resident in the top 13.3% state tax bracket, this exemption on a $50,000, 4.10% T-Bond is worth $270 annually compared to a similarly yielding corporate bond. Over a 10-year holding period, this amounts to over $2,700 in tax savings.
| Security | 1-Yr Gross Income | Real Return (post-2.7% inflation) | After-Tax Income (37% fed bracket) | After-Tax Return |
|---|---|---|---|---|
| 3-Month T-Bill | $485.79 | -1.73% | $388.63 | 0.78% |
| 1-Year T-Note | $1,825.00 | 0.95% | $1,149.75 | 2.30% |
| 10-Year T-Bond | $2,050.00 | 1.40% | $1,291.50 | 2.58% |
| 10-Year TIPS | $2,205.00 | 1.81% | $1,764.00 | 3.53% |
| I-Bond (composite) | $2,015.00 | 1.33% | $1,612.00 | 3.22% |
Reinvestment and Duration Risk in a Rate-Cutting Cycle
The primary risk facing income investors in 2025 is not default but reinvestment. With the Federal Reserve expected to implement two additional 25-basis-point rate cuts by mid-2026, short-term yields are projected to decline. An investor employing a "T-Bill ladder" or rolling 3-month bills faces significant yield compression. A 3.78% yield today could become 3.50% upon reinvestment in three months and potentially 3.25% by year-end 2026. This strategy creates a negative carry of 28-53 basis points relative to locking in a longer-term rate now, actively working against the goal of stable passive income.
For those selecting longer-duration instruments like 20- and 30-year bonds for their higher nominal yields (4.67% and 4.71%, respectively), the primary concern shifts to duration risk. A 30-year Treasury bond has a duration of approximately 18-22, meaning a 1% increase in prevailing interest rates would cause the bond's market price to fall by 18-22%. This level of price volatility is unsuitable for investors who may need to liquidate their position before maturity. These instruments should only be considered by those with a high degree of certainty they can hold the bond for its full 30-year term, collecting the semi-annual coupons and receiving par value at the end.
Advantages of Locking Duration
- Certainty: A 10-Year T-Bond at 4.10% guarantees that yield for a decade, eliminating reinvestment guesswork.
- Capital Appreciation: If rates fall as predicted, the market value of existing longer-duration bonds will increase.
- Simplified Management: Avoids the need for quarterly or semi-annual decisions on reinvesting matured T-bills at lower rates.
Drawbacks of Short-Term Rolling
- Reinvestment Risk: Directly exposed to falling short-term rates, leading to progressively lower income over time.
- Negative Real Returns: Current short-term yields already fail to compensate for inflation, eroding principal value.
- Active Management: Requires constant monitoring of auction schedules and market rates to redeploy capital.
Strategic Allocation by Investor Objective
The optimal Treasury security is dictated entirely by the investor's primary objective: capital preservation, maximum cash flow, or a balance of both. No single instrument serves all needs. For those prioritizing the preservation of purchasing power above all else, inflation-protected securities are non-negotiable. For investors requiring predictable, liquid monthly income to cover living expenses, nominal bonds offer higher cash flow and secondary market liquidity. A blended approach can often provide the best of both worlds.
| Investor Objective | Primary Security | Key Metric | Primary Trade-Off |
|---|---|---|---|
| Maximum Capital Preservation | 10-Year TIPS | 1.81% Real Yield | "Phantom income" taxed annually on principal adjustments. |
| Maximum Monthly Cash Flow | 10-Year or 30-Year T-Bond | 4.10% - 4.71% Nominal Yield | No inflation protection; principal value at risk from rising rates. |
| Highest Inflation Hedge | Series I-Bond | 4.03% Composite Rate | 1-year lockup period; 3-month interest penalty if sold before 5 years. |
| Balanced Income & Protection | 50% 10-Yr T-Bond / 50% 10-Yr TIPS | 1.61% Blended Real Return | Lower nominal cash flow than a pure bond portfolio. |
A balanced portfolio for a $50,000 allocation could consist of $25,000 in 10-Year T-Bonds and $25,000 in 10-Year TIPS. This structure would generate approximately $2,127 in gross annual income ($1,025 from the T-Bond and $1,102 from the TIPS, assuming 2.7% inflation). It provides a blended real return of 1.61%, offering a hedge against unexpected inflation while still capturing a solid nominal yield. Both securities are highly liquid on the secondary market, avoiding the lockup constraints of I-Bonds.
Purchase Procedures: TreasuryDirect vs. Brokerage
Investors have two primary channels for purchasing Treasury securities: directly from the government via TreasuryDirect or through a traditional brokerage firm. TreasuryDirect is a no-fee platform ideal for buy-and-hold investors, while brokerages offer greater flexibility and secondary market access.
Purchasing through a brokerage like Fidelity, Schwab, or Interactive Brokers offers distinct advantages. Investors can buy securities on the secondary market, allowing them to target specific maturity dates not available at auction. Selling before maturity is also simpler. Most major brokerages charge zero commission for new-issue auction purchases, making them cost-competitive with TreasuryDirect. However, secondary market purchases involve a bid-ask spread, typically a negligible 0.01-0.05% of face value. For UK residents, purchasing through a US brokerage that can properly handle W-8BEN forms is crucial to benefit from the US-UK tax treaty, which can reduce withholding on interest payments. While Treasury interest is exempt from US state taxes, UK investors should consult a tax advisor regarding their UK tax liability on this income.