Fixed annuities offer a guaranteed, predetermined interest rate for the full contract term — predictable but with no upside beyond the stated rate. Indexed annuities offer market-linked growth potential with principal protection, meaning you can receive more in strong market years but may receive zero in flat or down years. Indexed annuities typically have longer surrender periods (5–10 years vs 3–7 years for fixed annuities) and greater complexity. Fixed annuities are simpler and more predictable; indexed annuities offer greater growth potential but involve more moving parts.