What Is an Index Annuity?
An index annuity — more formally called a fixed indexed annuity (FIA) — is an insurance contract that links your interest credits to the performance of a stock market index such as the S&P 500. However, your premium is not invested directly in the market. The carrier uses a formula to translate index performance into credited interest, with a floor that prevents negative credits when the index falls.
How Interest Is Credited
Each contract year, the carrier measures the change in the linked index. If the index gained, you are credited a portion of that gain, subject to limits like a cap rate, participation rate, or spread fee. If the index lost value, the floor kicks in — most contracts credit 0% in down years, ensuring your accumulation value does not shrink due to market losses.
Index Annuities vs. Variable Annuities
Both link to market performance, but in very different ways. In a variable annuity, your money is actually invested in subaccounts and can lose value. In an index annuity, your premium is held in the carrier's general account, and only the interest calculation is linked to the index. This structural difference is why FIAs are called "fixed" annuities.
Index Annuities vs. Investing Directly in an Index Fund
Index funds offer full market participation — all the upside but also all the downside. An FIA offers partial participation (via caps or participation rates) but protects against any loss. The tradeoff is appropriate for those who want market-linked growth potential without the risk of losing principal.