I bonds: the government's inflation-linked piggy bank, with a clunky website

By Tom, CPA · Updated October 25, 2026

TL;DR: Series I savings bonds are bought electronically at TreasuryDirect, up to $10,000 per Social Security number per calendar year. The rate combines a fixed rate with an inflation rate reset every six months: 4.26% (0.90% fixed) for bonds issued May through October 2026. You must hold them 12 months, and cashing in before five years costs the last three months of interest.

Educational only, not tax, legal, or investment advice. Examples are illustrations, not predictions. Rules and limits change; verify current figures and talk to a qualified professional about your situation.

I bonds are the government's inflation-linked piggy bank: you lend Uncle Sam money, he promises to keep up with inflation plus a small fixed rate, and you never have to worry about the market value dropping. The catch is that the piggy bank has a one-year lock, an annual purchase limit, and a website that feels like it was designed in a time when "cloud" meant weather.

For early retirees, I bonds can be a useful part of the cash or emergency layer, and the tax deferral can be handy in low-income years. Here's what you need to know as of October 2026.

CPA Warning Label: I bonds are illiquid for the first year. Don't put money you might need in the next 12 months into them, no matter how attractive the rate looks.

Purchase limits

• $10,000 per year in electronic I bonds per Social Security number (or per EIN for entities like trusts or businesses).
• Electronic only: as of January 1, 2025, I bonds are only available electronically through TreasuryDirect. Paper I bonds are no longer sold.
• Minimum $25, then any amount to the penny.
• Per person, not per account: limits apply to the Social Security number of the first-named owner.

A married couple can buy $20,000 a year. Some people also buy through a revocable trust or a business with its own EIN, each of which has its own $10,000 limit. Gifts are another route: you can buy bonds as a gift to be delivered later, which counts toward the recipient's limit in the year it's delivered.

Rate components

The composite rate has two parts:

• Fixed rate: set when you buy and never changes for the bond's 30-year life.
• Inflation rate: reset every six months based on CPI-U changes.

For bonds issued May 1 to October 31, 2026, TreasuryDirect lists a composite rate of 4.26%, including a 0.90% fixed rate. A new rate is announced for bonds issued from November 1, so check TreasuryDirect for the latest figure before buying. The composite rate can never fall below zero, so the bond's value can't decline. Interest is earned monthly and compounds semiannually, and you collect it when you cash in the bond.

The fixed rate is the number that matters long term. A bond bought with a 0.90% fixed rate earns inflation plus about 0.9% for up to 30 years, a respectable real return for a risk-free, state-tax-free asset.

Holding period and penalty

TreasuryDirect's example: cash in after 18 months and you get the first 15 months of interest. Because interest posts monthly and the penalty is fixed at three months, cashing in right after the start of a new month is a little better than cashing in just before.

Tax deferral

• Federal income tax: yes, on the interest.
• State and local income tax: no.
• Timing: you choose whether to report interest every year or wait and report it all when you cash in or the bond matures (up to 30 years).
• Education exclusion: interest may be excluded if used for qualified higher education expenses and you meet income limits and other rules.
• Estate and gift taxes still apply.

For early retirees, deferral is the interesting part. You can buy I bonds while working in a high bracket, let interest accumulate untaxed, then cash them in during low-income years, when the interest might fall inside the standard deduction or the 10%/12% bracket. That's a small-scale version of the same strategy as a Roth conversion ladder: move income into years when it's cheap.

Illustration: a bond tent for the first retirement years

Illustration (assumptions): Larry and Fran each buy $10,000 of I bonds a year for four years before retiring, $80,000 total, while in the 24% bracket. Assume an average composite rate of 4% (hypothetical).

• After four to five years, the bonds might be worth roughly $90,000, with about $10,000 of accumulated interest.
• In their first retirement years, they cash in about $20,000 a year. The interest portion is taxed at their new low bracket, perhaps 10% or 12%, or offset entirely by the standard deduction, instead of 24% while working.
• No state tax on the interest at all.

The savings aren't huge, maybe $1,000 to $2,000 total, but the bonds also act as a no-volatility buffer during the risky first years of early retirement, when a stock crash would otherwise force selling at a loss.

Role in an emergency fund

I bonds make a decent second layer of an emergency fund, not the first:

• Layer 1: a few months of expenses in a high-yield savings account or money market fund, available immediately.
• Layer 2: I bonds older than 12 months, available within a few days, protected from inflation and market declines.
• Layer 3: taxable investments and Roth IRA contributions.

The 12-month lock is absolute, with very limited exceptions for disasters. If the money might be needed within a year, it belongs in Layer 1.

TreasuryDirect practicalities

• You need a TreasuryDirect account and a linked bank account. Identity verification can take time; set it up before you need it.
• Each person needs an individual account. A minor can have a linked account controlled by a parent.
• Add a beneficiary or second owner to each bond; it's easy to forget.
• Save your login details somewhere safe; account recovery can be slow.
• Track purchase dates so you know when each bond passes 12 months and 5 years.

Common mistakes

• Buying in late December expecting a full year's lock to end a few days later. The 12-month clock runs from the issue month; interest is credited as of the first of the month you buy, which helps, but you still wait 12 months.
• Forgetting to report deferred interest when you cash in. TreasuryDirect issues a Form 1099-INT for the year of redemption.
• Chasing the composite rate. A high inflation component lasts six months; the fixed rate lasts 30 years. Compare fixed rates when deciding whether to cash in old bonds and buy new ones.
• Skipping beneficiaries, which can make things harder for heirs.
• Treating I bonds as a growth asset. They protect purchasing power; they won't fund a 40-year retirement alone.

Should you cash in old I bonds?

Bonds bought in years when the fixed rate was 0% earn only inflation. If a new bond has a fixed rate near 1%, swapping can raise your real return, but only within the $10,000 annual purchase limit, after losing three months' interest if the old bond is under five years old, and after reporting all deferred interest. Older bonds with higher fixed rates are usually worth keeping.

I bonds vs alternatives

TIPS have no purchase limit and can be held in IRAs, which I bonds can't. For large inflation-protected allocations, TIPS often do the heavy lifting, with I bonds as a tax-deferred side dish.