Cap rates in indexed universal life (IUL) insurance set the maximum interest that can be credited to your cash value based on index performance in any given crediting period. If the linked index (commonly the S&P 500) returns more than the cap rate, you receive the cap rate — not the full index return. If the index returns less than the cap but more than zero, you receive the actual index return. If the index is negative, the 0% floor protects your cash value from market losses, though policy fees are still deducted.
Cap rates typically range from 8% to 12%, though they vary by carrier, product, and crediting strategy. Importantly, cap rates are not guaranteed for the life of the policy. Carriers reserve the right to adjust cap rates periodically, subject to a guaranteed minimum cap rate specified in the policy contract. When cap rates decrease, the potential for cash value growth is reduced. This is why reviewing both the current cap rate and the guaranteed minimum is important when evaluating IUL products.
IUL policies may also use participation rates and spread fees that further affect the interest credited. A participation rate determines what percentage of the index return is applied before the cap — for example, a 100% participation rate means the full index return (up to the cap) is credited, while an 80% participation rate means only 80% of the return is credited before the cap is applied. Spread fees are a flat percentage deducted from the index return before crediting. These mechanisms work together to determine your actual credited interest.
Understanding how cap rates, participation rates, and spreads interact is essential for evaluating IUL illustrations. Illustrations often show projected values at the current cap rate, which may not persist for the life of the policy. Reviewing the guaranteed column (which uses the guaranteed minimum cap rate) alongside the current column provides a more realistic range of potential outcomes. Guarantees are backed by the financial strength and claims-paying ability of the issuing insurance carrier.