I Bonds: The Inflation Hedge That Comes With an Expiration Date

There was a moment a few years back when I bonds became the hottest thing in personal finance. People who had never touched TreasuryDirect in their lives were hammering the website so hard it kept crashing. The Treasury had to extend deadlines. Grandparents were calling their grandkids asking how to set up an account.

That moment happened because inflation was running at 40-year highs and I bonds were paying north of 9%. That's not a typo. Nine percent. Guaranteed. From the U.S. government.

And then — as it always does — the story got more complicated.

Rates came down as inflation cooled. The limitations that nobody bothered reading about in 2022 started mattering again. People who'd piled in started asking: wait, can I get my money out yet? What happens now? Was this thing even worth it?

So let's slow down and actually explain what I bonds are, how the rate works, what the catches are, and — honestly — when they stop being the right tool for the job.

What Is an I Bond, Exactly?

An I bond — short for Series I Savings Bond — is a U.S. government savings bond designed specifically to protect your purchasing power against inflation. You buy it, you earn interest, and that interest adjusts every six months based on the Consumer Price Index for All Urban Consumers (CPI-U).

That's the key feature. Unlike a regular savings account or a CD, the return on an I bond isn't fixed. It moves with inflation. When prices rise fast, you earn more. When inflation cools, you earn less.

You buy them directly from the U.S. Treasury at TreasuryDirect.gov. There's no middleman, no brokerage fee, no commission. You're lending money directly to the federal government, which — whatever you think of Washington — isn't going to default on a $10,000 savings bond.

How the rate is calculated

The I bond rate has two components that get added together:

1. The fixed rate. This is set by the Treasury every May and November and stays locked in for the life of the bond. It can be zero — and often has been. When you buy determines which fixed rate you lock in forever.

2. The inflation rate. This adjusts every six months (in May and November) based on the trailing six-month change in CPI-U. This portion floats with inflation for as long as you hold the bond.

The formula looks scarier than it is: the composite rate = fixed rate + (2 × semiannual inflation rate) + (fixed rate × semiannual inflation rate). That last term is tiny and basically rounds to nothing. The practical answer is: add the fixed rate and twice the six-month inflation number.

Here's what that looked like at the peak in November 2022: a fixed rate of 0.40% plus an annualized inflation adjustment of about 6.48%, producing a composite rate of 6.89%. Before that, in May 2022, the composite rate hit 9.62% — that's the number that broke the TreasuryDirect website.

The Rules You Need to Know Before You Buy

I bonds come with a specific set of rules that can feel like fine print until they're suddenly very relevant to your life.

Purchase limits. You can buy up to $10,000 per person per calendar year in electronic I bonds. There's also a paper bond option — up to $5,000 per year using your federal tax refund — but most people go electronic. Married? You can each buy $10,000, giving you $20,000 per household per year. You can also buy for a trust or a child, which opens up some legitimate strategies for families.

Minimum holding period. You cannot touch your money for 12 months. Full stop. Buy in January, and you're locked until at least the following January. This makes I bonds completely wrong for an emergency fund or any money you might need before that year is up.

Early redemption penalty. If you redeem before five years, you forfeit the last three months of interest. So if you cash out at 18 months, you only keep 15 months' worth of interest. After five years, you keep everything. After 30 years, the bonds stop earning interest entirely and you should absolutely cash them out.

Tax treatment. Interest is subject to federal income tax but exempt from state and local taxes — a meaningful advantage if you live somewhere with a high state tax rate. You can defer federal taxes until you cash out (or the bond matures), which gives you some control over when you take the tax hit. There's also an education exclusion that can make the interest tax-free if you use it to pay qualifying tuition expenses, subject to income limits.

Why They Mattered So Much — and Why History Keeps Repeating

The 2022 I bond rush wasn't the first time these instruments had a moment. They were introduced in 1998, partly as a response to inflation fears that turned out to be overblown at the time. For years they sat quietly, paying modest rates, barely mentioned outside of government finance geek circles.

Then inflation actually arrived. And suddenly a savings instrument that automatically kept pace with CPI looked genius.

Here's the honest history though: for most of the 2010s, I bond rates were embarrassingly low. There were stretches where the composite rate was under 1.5%. Anyone holding I bonds from that era wasn't getting rich — they were basically parked in something that beat nothing but didn't beat much else.

That's the pattern. I bonds shine when inflation spikes. They're merely okay in calm environments. And they can feel like dead weight during deflationary scares, when the inflation component flirts with zero and your total return lives or dies on whatever fixed rate you locked in when you bought.

The lesson from history is that the fixed rate matters a lot more than people give it credit for in the moment. Buying in May 2022 when the composite rate was 9.62% felt incredible — but you also locked in a 0% fixed rate. Buying in May 2000 when the fixed rate was 3.60% felt boring, but that 3.60% is yours forever on top of every inflation adjustment for 30 years.

I Bonds vs. the Competition

I bonds don't exist in a vacuum. Before you commit your $10,000 (and potentially your spouse's $10,000), it's worth running them against the alternatives.

TIPS (Treasury Inflation-Protected Securities) are the institutional cousin. They're actual bonds you buy through a brokerage, they adjust for inflation too, and they don't have the $10,000 annual cap. But TIPS trade in the market, which means their price fluctuates — you can lose money on TIPS in the short run even if inflation is rising. I bonds don't have that problem. The value never goes negative. That floor is real and valuable.

High-yield savings accounts have become serious competition in rate environments where the Fed has kept its benchmark rate elevated. In 2023 and 2024, online high-yield savings accounts were offering 4.5%–5.5% APY with zero lock-up period. Hard to argue with that when I bond rates had already fallen back to the 4–5% range. The flexibility alone tips the scales.

CDs offer fixed rates and predictability, but they don't auto-adjust for inflation. If inflation surprises to the upside, a 5% CD looks weaker in hindsight.

| Feature | I Bonds | TIPS | High-Yield Savings | CDs |

|---|---|---|---|---|

| Inflation protection | Automatic | Automatic | None | None |

| Principal at risk | No | Yes (market price) | No | No |

| Annual purchase cap | $10,000 | None | None | None |

| Lock-up period | 12 months minimum | None | None | Term varies |

| Early exit penalty | 3 months interest (if < 5 yrs) | Market price fluctuation | None | Varies |

| State tax exempt | Yes | Yes | No | No |

| Liquidity | Low | High | Very High | Low–Medium |

The table above is why I bonds aren't the universal answer. They're a specific tool for a specific job.

When I Bonds Actually Make Sense

Let me be direct about this: I bonds make the most sense when at least two or three of these conditions are true at the same time.

Inflation is elevated and expected to stay elevated. The whole pitch is inflation protection. If inflation is already cooling fast, you might buy in just as the rate drops to something unimpressive.

The fixed rate is meaningfully above zero. Check what fixed rate the Treasury is offering before you buy. A fixed rate of 1%+ on top of inflation adjustments compounds nicely over 30 years if you plan to hold long term.

You have money you won't need for at least a year — ideally three to five. The 12-month lock-up is non-negotiable. The three-month penalty before five years is a real cost. If this money has any chance of being needed before those thresholds hit, don't buy an I bond with it.

You've already maxed out tax-advantaged accounts. I bonds aren't a retirement account. They don't give you a deduction. If you still have room in a 401(k), HSA, or IRA, that's probably a better place for extra savings dollars first.

You're in a high state-tax state. The state income tax exemption has actual dollar value. In California or New York, that adds roughly 9–13% of your interest income back into your pocket compared to a taxable savings account.

The connection between bond yields and inflation dynamics is something worth watching broadly — not just for I bonds but for any fixed-income decision. As I wrote in the analysis of Oil, Bonds, and a Strait You Should Know by Name, oil price shocks feed directly into CPI, which flows into I bond rates with a six-month lag. Understanding that transmission mechanism helps you anticipate when I bond rates might spike — or fall.

When I Bonds Stop Making Sense

Just as important as knowing when to buy is knowing when to stop holding — or never buy at all.

When the composite rate falls below what high-yield savings will pay you. This happened in 2023. If your bank (or an online bank) is offering 5% on a savings account you can access any day, and the I bond is paying 4.3% with a 12-month lock, the math isn't there anymore. The premium for illiquidity has inverted.

When you need flexibility. The market doesn't always cooperate with your five-year plan. Layoff, medical bill, car engine, down payment timeline — life has a way of needing money exactly when it's inconvenient. An I bond is a bad emergency fund.

When inflation is likely to undershoot. If the Federal Reserve has been aggressive with rate hikes and the economy is clearly slowing, the trailing CPI that sets I bond rates may be backward-looking. You could lock in at a decent rate only to watch the next six-month reset come in near zero. This isn't guaranteed — forecasting inflation is genuinely hard — but it's worth considering.

When the fixed rate is zero and the composite rate looks high only because inflation is temporarily elevated. A 9% composite rate with a 0% fixed is nine percent for one six-month period — then it adjusts. Don't mistake a one-period rate for a multi-year lock.

After 30 years. Once the bond matures, it pays nothing. If you've had one sitting in an old TreasuryDirect account and forgotten about it, check the issue date. Some people have been holding bonds that stopped earning interest years ago.

The Bigger Picture: What I Bonds Actually Are

Strip away all the mechanics and here's the real deal: I bonds are a government savings instrument designed for patient, inflation-nervous savers with a time horizon of at least a few years.

They're not a high-yield investment. They're not a trading vehicle. They're not going to make you rich or save a poorly constructed portfolio. What they do — and do well in the right conditions — is preserve purchasing power without risking principal. That's a narrow but genuinely useful job.

Think of them the way you'd think about a fire extinguisher. You don't keep it because you expect a fire. You keep it because if there is one, nothing else in the kitchen is going to do what it does.

The 2022 moment was real. People who bought Series I bonds in the first half of that year and held them through 2024 came out ahead of most savings alternatives over that window. But people who expected that environment to last forever, or who ignored the $10,000 cap and looked for workarounds, or who bought in late 2023 when the rate had already collapsed — they got a different experience.

Know what you're buying. Know why you're buying it. And always know what the rate is going to do when the next six-month window kicks in.

FAQ

How often does the I bond interest rate change?

Twice a year — every May and November. The Treasury announces a new composite rate based on the latest six months of CPI-U data. Your bond's rate doesn't change the moment Treasury announces a new rate; it resets on a six-month schedule tied to your specific purchase date. So if you bought in March, your rate resets every March and September, not every May and November. The fixed rate portion never changes after you buy — only the inflation component adjusts.

Can you lose money on I bonds?

Not in nominal terms — the principal is fully guaranteed by the U.S. government and the value of an I bond can never go below what you paid. In real terms (purchasing power), it's theoretically possible but very unlikely since the bond is explicitly designed to track inflation. The one real "loss" scenario is behavioral: if you redeem before five years, you forfeit three months of interest. Buy in a bad month, redeem at an inconvenient time, and your effective annualized return could be lower than a simple savings account. But you won't get back less than you put in.

What's the difference between I bonds and TIPS?

Both protect against inflation, but they work differently and serve different investors. TIPS are marketable Treasury securities — they trade on the open market, their price fluctuates with interest rate changes, and you can lose money if you sell before maturity. I bonds are non-marketable savings bonds: no secondary market, no price volatility, no risk to principal. TIPS have no purchase limit and are better for large portfolios or institutional uses; I bonds are capped at $10,000 per person per year. TIPS can be held in an IRA; I bonds cannot. For most individual savers, the simplicity and principal protection of I bonds makes them easier to hold — if you can live with the liquidity constraints.

Is there a way to buy more than $10,000 in I bonds per year?

Technically yes, but the extra options are limited. You can buy an additional $5,000 in paper I bonds using your IRS tax refund — so an individual could reach $15,000 in a single year, or a married couple $25,000 if both use their refunds. You can also buy I bonds in the name of a trust, and separately in the name of a child (as custodian). Beyond that, there's no legitimate way to exceed these caps for personal accounts. The limits exist by design — this program isn't meant to be a large-scale investment vehicle.

What happens to I bonds when the owner dies?

I bonds can be transferred to a named co-owner or beneficiary on the account. If you've set up TreasuryDirect correctly with a designated beneficiary, the bond passes to that person without going through probate. The surviving co-owner or beneficiary can then hold the bond to maturity, cash it out, or leave it earning interest. If no beneficiary is named, the bonds become part of the estate and go through whatever process your state requires. This is one of the administrative details that's easy to overlook when you're excited about a 9% rate and much more important than it sounds.