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I Bonds vs. TIPS: which inflation-protected security wins in 2026?
Both are inflation-protected. They behave very differently in your portfolio. Here's the 2026 math on rates, taxes, and which to pick for what.
I Bonds and TIPS are the two ways the U.S. Treasury sells inflation protection to retail investors.They sound similar. They're very different products — different purchase mechanics, different tax treatment, different risk profiles.
The short answer most people need: I Bonds for your emergency fund and short-term taxable savings, TIPS inside tax-advantaged accounts for longer-duration inflation hedging. The rest of this guide is the math behind that rule and the cases where it flips.
The 30-second version
| Feature | I Bonds | TIPS |
|---|---|---|
| Where you buy | TreasuryDirect only | Any brokerage; TreasuryDirect; bond funds |
| Annual purchase cap | $10K electronic + $5K paper | None |
| Maturity | 30 years (1-yr lock; 5-yr penalty) | 5, 10, or 30 years |
| Market price risk | None — Treasury redeems at face | Yes — moves with real yields |
| Inflation adjustment | Variable rate, reset semi-annually | Principal adjusts with CPI |
| Federal tax | Deferred until redemption | Annual (coupon + inflation adj) |
| State/local tax | Exempt | Exempt |
| Best account | Taxable | Tax-advantaged (Roth IRA, 401(k)) |
How I Bonds work
An I Bond is a U.S. savings bond with a composite interest rate made up of two pieces: a fixed rate set at purchase (lasts the life of the bond) and a variable inflation rate derived from CPI-U, reset every May 1 and November 1.
The composite rate is: fixed + (2 × semi-annual inflation) + (fixed × semi-annual inflation). In practice, the variable piece dominates: a 1.20% fixed rate paired with 1.55% semi-annual inflation produces a composite of roughly 4.32% for that six-month window.
- 1-year lockup. You can't redeem at all in the first 12 months.
- 5-year penalty. Redeem before five years and you forfeit the last three months of interest.
- Tax deferral. Interest accrues monthly but isn't taxed federally until you redeem (or 30 years passes).
- Education exclusion. If you use the proceeds for qualified higher-education expenses and meet the income limits, interest can be federally tax-free.
The buying constraint matters. You buy I Bonds at TreasuryDirect.gov — a federal site with 1990s UX. The $10K cap is per Social Security number per calendar year. A married couple maxes at $20,000 plus the $5,000 paper allotment from their tax refund.
How TIPS work
TIPS are regular Treasury securities— auctioned by the Treasury, traded on the secondary market through any brokerage, priced and yielded daily. The twist: the bond's principal value adjusts up (or down) with CPI-U each month.
Coupons are paid semi-annually as a fixed percentage of the inflation-adjusted principal. So if you own a 10-year TIPS with a 1.5% coupon and CPI is up 4% over a year, the principal grows to $10,400 and the coupon pays 1.5% of that. Inflation compounds inside the bond.
The catch is taxes.The annual principal adjustment is federally taxable in the year it happens, even though you don't receive the cash until maturity. This is the "phantom income" problem. In a taxable account, you pay tax on inflation gains you haven't yet realized. In a Roth IRA or 401(k), this is a non-issue.
The fixed-rate decision (I Bonds)
The variable inflation piece is the same for everyone who buys in a given window. What differs is the fixed rate at purchase, which sticks for 30 years. Recent fixed rates have ranged from 0.00% (May 2020) to 1.30% (Nov 2023). The current 1.20% (May 2026) is historically generous.
A 1.20% fixed real rate, locked for 30 years, with state/local tax exemption — that's a strong floor under your purchasing power. If fixed rates fall in November, today's buyers keep the higher floor for life.
The phantom-income problem (TIPS)
Say you buy a $10,000 10-year TIPS with a 1.5% coupon. CPI rises 4% in year one, adjusting principal to $10,400.
- Cash received: ~$156 (1.5% of $10,400) coupon, paid out.
- Cash NOT received: $400 principal adjustment, locked inside the bond until maturity.
- Federally taxable: $156 + $400 = $556.
At a 24% marginal bracket, you owe $133 in federal tax on income that includes $96 you'll only see in 9 more years. In a taxable account, this drag is real. In a Roth IRA, it's irrelevant. Hold TIPS in tax-advantaged accounts.
When I Bonds are the right call
- Inflation-protected emergency fund overflow. The 1-year lockup is the only deal-breaker; if you can park $10K behind the rest of your liquid emergency fund, I Bonds beat any HYSA on after-tax real return.
- Short-to-medium horizon (1–10 years) in a taxable account. Tax deferral and no price risk make the after-tax return predictable.
- You want a guaranteed real return floor. The 1.20% fixed real rate is locked for 30 years.
- College savings (with income limits). Federal exclusion when proceeds fund qualified higher-education expenses, subject to MAGI phase-outs.
See best HYSAs 2026 for the liquid side of the bucket.
When TIPS are the right call
- Inside a Roth IRA or 401(k). Phantom income disappears; you get the inflation adjustment tax-free at withdrawal (Roth) or deferred (Traditional).
- You're investing more than $10K/year in inflation protection. The I Bond cap forces you into TIPS once the bucket grows.
- Building a TIPS ladder for retirement. Buy individual TIPS maturing each year of retirement to lock in inflation-adjusted real income.
- You want a long duration hedge. 30-year TIPS give true long-duration inflation protection no other Treasury product offers.
The tax-equivalent math
Both products are state-tax-exempt. For a NY/CA/IL resident in a high bracket, that exemption alone is worth ~10% on the after-tax yield versus a CD or corporate bond.
Use the tax bracket calculatorto translate a stated Treasury yield into the equivalent fully-taxable yield you'd need from a corporate bond to match it after state tax. The gap is often the deciding factor for high earners in high-tax states.
Common mistakes
Mistake 1: Buying TIPS in a taxable account and being surprised by the K-1 -style phantom-income tax bill. Move them to a Roth IRA or hold a TIPS fund (SCHP, VTIP) that distributes the inflation adjustment as taxable income each year — still suboptimal in taxable, but no maturity-year shock.
Mistake 2: Treating I Bonds as liquid. The 1-year lockup is absolute. Build a liquid emergency fund in a HYSA first, then add I Bonds for the next tier.
Mistake 3: Selling TIPS before maturity in a panic. If real yields rise, TIPS prices fall; selling locks in the loss. Either hold to maturity or hold short-duration TIPS funds (VTIP) where rate sensitivity is small.
Where to buy
I Bonds: TreasuryDirect.gov is the only option. Plan for the government-grade UX.
TIPS: Any major brokerage. Buy individual TIPS at Treasury auction (no commission), on the secondary market, or via a low-cost TIPS fund/ETF:
For a one-ticket TIPS solution: Schwab's SCHP (0.03% ER), Vanguard's VTIP (0.04% ER, short-duration), or Vanguard's VAIPX (0.06% ER) all give broad TIPS exposure for negligible cost.
The bottom line
Fund $10K of I Bonds per spouse per year for short-to-medium taxable inflation protection. After that, layer in TIPS inside a Roth IRA or 401(k) for longer duration and uncapped exposure. The two products are complements, not substitutes — I Bonds give you a guaranteed real floor in taxable, TIPS give you scalable inflation hedging in tax-advantaged accounts.
Related reading
- Best HYSAs 2026 — the liquid layer that should come before I Bonds.
- How big should your emergency fund be? — sizing the buckets.
- Asset allocation by age — where inflation protection fits in the bigger portfolio.
- Sequence-of-returns risk — why retirees especially need real (not nominal) returns.
- Qualified vs. ordinary dividends — the broader picture on how investment income is taxed.
- Roth vs. Traditional IRA — picking the right wrapper for TIPS.
Frequently asked questions
- What's the simplest difference between I Bonds and TIPS?
- I Bonds are non-marketable savings bonds you buy directly from TreasuryDirect — they can't be sold or lose principal. TIPS are marketable Treasury securities whose principal adjusts with CPI; you can buy and sell them on the secondary market through any brokerage, and their market price moves with real interest rates.
- How much can I buy in I Bonds each year?
- $10,000 per person, per year electronically through TreasuryDirect, plus up to $5,000 in paper I Bonds bought with your federal tax refund. A married couple can buy $20,000 plus $5,000 in paper bonds, and you can buy additional I Bonds in the name of a trust or a child.
- Are I Bonds and TIPS both tax-advantaged?
- Both are exempt from state and local income tax. I Bond interest is federal-deferred until you redeem the bond (you can also defer for college expenses). TIPS coupon payments AND the annual principal adjustment are federally taxable each year — that's the phantom-income problem, which is why TIPS are best held in tax-advantaged accounts.
- When are I Bonds the better choice?
- When you're holding inflation-protected money for 1–10 years in taxable, value capital preservation over yield, and don't want to think about reinvestment risk. The fixed-rate component (currently 1.20%) plus CPI gives a guaranteed real return with no price volatility.
- When are TIPS the better choice?
- When you have more than $10,000 to put to work in a single year, you're investing inside a Roth IRA or 401(k), and you want a longer-duration inflation hedge (10–30 years). TIPS ladders also give you scheduled inflation-adjusted cash flows during retirement.
- Can I lose money on TIPS?
- Yes. TIPS prices move inversely with real interest rates. If you buy a 10-year TIPS at a 2% real yield and real yields rise to 3%, the market value falls. Hold to maturity and you'll get the inflation-adjusted principal back; sell early and you can take a real loss. I Bonds have no such risk — TreasuryDirect always redeems at face plus accrued interest.