I Bonds vs. Treasury Inflation-Protected Securities (TIPS) vs. a TIPS Exchange-Traded Fund (ETF): Which Protects $15,000 From Inflation for 5 Years?

9 min read · Last updated September 29, 2026

I bonds are the better inflation hedge for amounts under $10,000 that can sit untouched for at least a year. Once the balance is larger, or the money might need to move before a fixed date, TIPS or a TIPS ETF wins instead.

In this article

• Series I Savings Bonds: A $10,000-a-Year Cap With a Government Floor
• Buying TIPS at Auction: No Cap, but a Tax Bill on Money You Have Not Received
• A TIPS ETF: Daily Liquidity, No Deflation Floor
• Choose I Bonds, TIPS or a TIPS ETF: The Verdict
• What Could Change This Calculus
• Frequently asked questions

Three government-backed tools protect savings from inflation. The first is a Series I savings bond bought directly from the U.S. Treasury. The second is a Treasury Inflation-Protected Security (TIPS) bought at auction. The third is a TIPS exchange-traded fund (ETF) held in a regular brokerage account. Picture $15,000 you will not touch for five years. The first fork in the decision is a hard number. I bonds cap purchases at $10,000 per Social Security number per calendar year, so the other $5,000 has to go somewhere else no matter what. From there, the choice turns on three things: a 12-month lockup, daily liquidity, and paying tax on gains you have not received yet.

Series I Savings Bonds: A $10,000-a-Year Cap With a Government Floor

The Series I savings bond pays a composite rate. That rate combines a fixed rate, locked for the bond’s full 30-year life, with an inflation rate tied to the Consumer Price Index. The inflation portion resets every six months. For bonds issued from May 1, 2026 through October 31, 2026, that composite rate is 4.26%, built from a 0.90% fixed rate, according to TreasuryDirect’s I bonds page. You can buy I bonds for as little as $25. The maximum is $10,000 electronically per Social Security number or Employer Identification Number each calendar year. As of January 1, 2025, they are sold only in electronic form through a TreasuryDirect account, the same source confirms.

You cannot cash an I bond in the first 12 months at all. Redeem one before five years and you forfeit the last three months of interest, a penalty that disappears entirely once you cross the five-year mark. The bond keeps earning for 30 years if you never touch it. Every six months, TreasuryDirect recalculates the composite rate. If a sharp deflationary period would otherwise push that combined rate below zero, the formula stops at zero instead. That means the bond’s value never shrinks, even in deflation, per TreasuryDirect’s I bond rate explainer. Interest is exempt from state and local income tax. Federal tax is deferred until you cash the bond or it matures, whichever comes first.

Buying TIPS at Auction: No Cap, but a Tax Bill on Money You Have Not Received

TIPS are sold in 5-, 10-, and 30-year terms. The minimum purchase is $100, and the non-competitive bid ceiling is $10 million, so there is no practical cap for an individual saver, per TreasuryDirect’s TIPS page. The coupon rate is fixed at auction and pays out every six months. It is applied to a principal that moves with the Consumer Price Index rather than staying flat. In the most recent 10-year TIPS reopening auction, on September 17, 2026, the coupon was set at 2.375%. The high real yield awarded to bidders came in at 2.653%, on a note maturing July 15, 2036, according to TreasuryDirect’s own auction data. Those are two different numbers: the coupon is what you are paid twice a year, and the real yield is the return built into the price you paid at auction.

The deflation protection here only applies at maturity. If deflation shrinks the adjusted principal below the original face value during the life of the bond, your semiannual coupon payments shrink along with it. You could also sell at a loss before maturity. Hold to maturity, though, and you are guaranteed the greater of the inflation-adjusted principal or the original amount, per the same TreasuryDirect page. The tax catch is real. The Internal Revenue Service (IRS) requires you to report each year’s increase in the inflation-adjusted principal as taxable original issue discount, per IRS Publication 550. You will not actually receive that cash until the bond matures or you sell it. Savers call this phantom income, and it is the single biggest reason advisors push individually held TIPS into an individual retirement account (IRA) rather than a taxable account.

A TIPS ETF: Daily Liquidity, No Deflation Floor

A TIPS ETF holds a rolling basket of TIPS across multiple maturities. It trades on an exchange like a stock, with no purchase cap, no minimum hold, and no auction schedule to work around. The iShares TIPS Bond ETF, one of the largest funds in the category, charges a 0.18% annual expense ratio and pays its distributions monthly, according to the fund’s own product page. Because the fund realizes its inflation adjustments and passes them through as regular taxable income, you receive cash along the way. You are not stuck owing tax on gains locked inside a bond you have not sold.

That convenience comes at a cost. There is no maturity date, so there is no floor guaranteeing you get your principal back. A TIPS ETF’s price is marked to market every trading day. It can fall if real interest rates rise, even during a period of positive inflation, because the fund never holds any single bond to term. If you need this money to sit somewhere for less than a year, none of these three tools is the right fit. A high-yield savings account, money market account, or short-term Treasury bill works better for that shorter horizon, as our comparison of those three cash tools lays out.

Factor	I Bond	TIPS (auction)	TIPS ETF
Purchase limit	$10,000 per year per Social Security number, electronic only	$100 minimum, up to $10 million non-competitive	No cap, price of one share
Access to your money	Locked 12 months; penalty before 5 years	Sellable on the secondary market before maturity	Sellable any trading day
Deflation protection	Composite rate floored at 0% every 6 months	Principal never below par, but only guaranteed at maturity	None; share price moves daily with real rates
Inflation adjustment	Built into the twice-yearly composite rate	Principal adjusted to the Consumer Price Index daily	Reflected in the fund’s daily net asset value
Tax on the inflation gain	Deferred until redemption or maturity, federal only	Owed each year it accrues, before you receive the cash	Paid out monthly as taxable income, no deferral
Best for	Amounts under $10,000 you can lock up 12+ months	Larger sums with a known target maturity date	Money you might need before a fixed date, or brokerage/IRA accounts

Choose I Bonds, TIPS or a TIPS ETF: The Verdict

Choose I bonds if your total fits under the $10,000-per-person annual cap. You need to commit to at least 12 months without touching the money, and you want a floor that guarantees the bond’s value never falls, even in deflation.

Choose TIPS at auction if you have more than $10,000 to place and want a specific real yield locked to a known maturity date, such as 2036. Hold the bond inside an IRA or other tax-advantaged account to sidestep the yearly tax bill on principal you have not received.

Choose a TIPS ETF if you need the option to sell before a fixed maturity. It also fits if you are already investing through a brokerage or retirement account, or you would rather spread inflation exposure across many maturities than commit to a single auction result.

What Could Change This Calculus

The I bond’s fixed rate resets every May 1 and November 1, so a jump or drop in the next announcement changes how competitive it is against a fresh TIPS auction. A move into a higher federal tax bracket makes the TIPS phantom income problem more expensive and makes the I bond’s tax deferral more valuable by comparison. A sharp change in the Consumer Price Index reading can also swing things fast. A spike in inflation lifts every option’s payout. A sudden deflationary quarter tests the I bond’s zero floor and the TIPS ETF’s lack of one, at the same time.

Frequently asked questions

Can I buy more than $10,000 in I bonds in one year? Not under one Social Security number. The cap is $10,000 per year per Social Security number or Employer Identification Number for electronic I bonds. A spouse with a separate registration has an independent $10,000 cap, but any amount beyond what fits under these limits has to go into TIPS or a TIPS ETF instead.

Do I owe tax on a TIPS bond before I actually get paid? Yes. The Internal Revenue Service treats any yearly increase in a TIPS’s inflation-adjusted principal as taxable original issue discount, reportable the year it accrues. You will not actually receive that money in cash until the bond matures or you sell it.

What happens to TIPS or a TIPS ETF if deflation hits? An individually held TIPS guarantees you get back at least the original principal, but only if you hold it to maturity; sell early during deflation and you can take a loss. A TIPS ETF has no maturity date at all, so its price can keep falling as long as real rates stay elevated.

Is a TIPS ETF a good substitute once I hit the I bond cap? Yes, for money above the $10,000 annual limit. You give up the I bond’s zero-rate floor, but you gain daily liquidity, no 12-month wait, and monthly taxable distributions instead of a tax bill on money you have not yet received.

Which option best protects money for exactly five years? An individual TIPS with a maturity matched to your five-year target gives the most precise guarantee. I bonds can be held past five years penalty-free but are capped at $10,000 a year. A TIPS ETF has no fixed maturity, so its price will still move around at the five-year mark.