TIPS Explained: How Treasury Inflation-Protected Securities Actually Work

When inflation surges, fixed-rate bonds lose purchasing power fast. Treasury Inflation-Protected Securities, or TIPS, were created specifically to address that problem. Issued by the U.S. Department of the Treasury since 1997, TIPS are backed by the full faith and credit of the U.S. government, but unlike a standard Treasury note or bond, their principal value moves with inflation rather than staying fixed.

How the inflation adjustment works

Every TIPS bond has a stated face value, known as par, typically $1,000 per bond at issuance. That principal is adjusted twice a year based on changes in the non-seasonally adjusted Consumer Price Index for All Urban Consumers, or CPI-U, which is published monthly by the Bureau of Labor Statistics. If CPI-U rises, the bond's principal increases; if CPI-U falls, the principal decreases, though a floor exists at maturity that guarantees the original face value back even in a deflationary environment.

Interest, called the coupon, is paid semiannually at a fixed real rate that is set at auction and does not change over the life of the bond. But because that rate is applied to the adjusted principal rather than the original face value, the dollar amount of each interest payment rises when inflation has pushed the principal higher, and falls when the principal has been adjusted downward.

A simplified example

• A 10-year TIPS is issued with a $1,000 face value and a 1.5% real coupon rate.
• If cumulative inflation over the following year pushes the adjusted principal to $1,030, the next interest payment is calculated as 1.5% of $1,030, not of the original $1,000.
• At maturity, the investor receives the inflation-adjusted principal at that time, or the original $1,000, whichever is higher.

The tax treatment that surprises many investors

This is arguably the most important thing for retail investors to understand before buying TIPS in a taxable brokerage account. Under Internal Revenue Service rules, the annual increase in a TIPS' principal from inflation adjustments is treated as taxable interest income in the year it occurs, even though the investor does not actually receive that money until the bond matures or is sold. This is sometimes called 'phantom income.' Investors receive a Form 1099-OID reporting this imputed income, and it must be reported on their tax return for that year. Because of this feature, many financial professionals and the Treasury itself note that TIPS are often better suited to tax-advantaged accounts, such as IRAs or 401(k)s, where the annual inflation adjustment is not currently taxable.

How to buy TIPS

• Directly from the U.S. Treasury through TreasuryDirect.gov, in $100 increments, at scheduled auctions with no fee.
• Through a brokerage account on the secondary market, where prices fluctuate based on real interest rates and demand.
• Via TIPS mutual funds or exchange-traded funds, which offer diversification across maturities and daily liquidity but charge an expense ratio and do not guarantee return of principal at a specific date the way an individual bond does.

The breakeven inflation rate

Investors and economists commonly compare the yield on a TIPS to the yield on a nominal Treasury of the same maturity to calculate what's known as the breakeven inflation rate, a rough market-based estimate of expected average inflation over that period. The Federal Reserve Bank of St. Louis and other Federal Reserve research departments publish and track these breakeven rates as one input, among many, into assessing inflation expectations, though they are not a perfect predictor and can be influenced by liquidity and risk premiums rather than inflation expectations alone.

Risks and tradeoffs

• Interest rate risk: like any bond, TIPS prices can fall if real interest rates rise, even if inflation is also rising.
• Deflation scenario: the inflation adjustment can reduce interim principal and coupon payments, though the final maturity payment is protected at par.
• Liquidity: TIPS trade less frequently than standard Treasurys, which can widen bid-ask spreads in the secondary market.
• Tax drag: as noted above, phantom income in taxable accounts can create a tax bill before any cash is received.

TIPS are not a bet on the direction of inflation so much as a tool for reducing uncertainty about future purchasing power. For long-term savers, particularly those building retirement income streams inside tax-advantaged accounts, they remain one of the few instruments explicitly designed and guaranteed by the U.S. government to track consumer inflation. As with any fixed-income decision, investors should weigh their own time horizon, tax situation, and overall portfolio construction, and this article does not constitute investment advice.