Caps, Participation Rates and Spreads: How Index Credits Shrink

Indexed annuities are often described as letting you share in market gains without market losses. The sharing is real, but it is partial, and the contract decides how partial. Caps, participation rates and spreads are the levers that turn an index's return into the credit that lands in your account.

This guide explains each lever using the examples regulators themselves publish, then covers the downside features of registered index-linked annuities (RILAs) and the reasons these numbers can change after you buy. It is general information, not financial, insurance, tax or legal advice. For a specific contract, read the contract and any prospectus, and contact your state insurance department or a licensed professional with questions.

Why your credit isn't the index's return

The SEC's investor bulletin on indexed annuities (July 31, 2020) gives two main reasons an indexed annuity may be credited with less than the index gained.

First, dividends are usually excluded. Gains in the index are generally calculated without including dividends paid on the securities that make up the index. The 2020 bulletin's example: an index reports a 7% total return for a year, but 2.5 percentage points came from dividends, so many indexed annuities would count 4.5% as the index's return.

Second, only a portion of the index's performance is usually credited. That is where the three limits below come in. The bulletin notes that these features can reduce your return the same way a direct fee would, even if the annuity is called a "no fee" annuity.

Participation rates, caps and spreads

Participation rate. The participation rate decides how much of the index gain is credited to your annuity. In the SEC's 2020 example, a 75% participation rate applied to a 10% index return produces a 7.5% credit. FINRA's article on indexed annuities (July 14, 2022) describes it the same way: with a 75% participation rate, index-linked returns amount to only 75% of the index's gains.

Rate cap. A cap is the maximum positive return the contract can earn for a period. The SEC's 2020 example: with a 7% cap, an index return calculated at 12% produces a 7% credit. FINRA's 2022 article makes the same point: caps mean that during big bull markets, your returns won't climb with the index.

Spread, margin or asset fee. A spread subtracts a set percentage from any index gain. The SEC bulletin says it is sometimes called the margin, spread, asset fee or administrative fee. In its 2020 example, a 3% spread applied to a 9% index return leaves a 6% credit.

Contracts can combine these. The SEC's 2020 combined example uses a 75% participation rate and a 3% spread on a 10% index return: 75% of 10% is 7.5%, minus 3% leaves 4.5%. In other words, more than half of that year's index gain never reaches the contract.

Crediting methods and terms

How the index's change is measured matters too. The SEC's 2020 bulletin describes two common methods. Point-to-point compares the index level at two moments, such as the start and end of the term. Averaging compares an average of index levels taken at intervals during the term with the level at the start. The bulletin says terms are typically twelve months but can vary.

Timing creates a trap: the bulletin warns that if you take money out before a term ends, not all of that term's return may be applied. FINRA adds that the variety and complexity of crediting methods can make it difficult to compare one indexed annuity to another.

The downside: guarantees, floors and buffers

Fixed indexed annuities and RILAs handle losses very differently.

For fixed indexed annuities, Investor.gov's annuities page (as viewed in October 2026) says the interest rate credited is guaranteed never to be less than zero, even if the market goes down. FINRA's 2022 article says the guaranteed minimum interest rate on these products usually ranges from 1 to 3 percent on at least 87.5 percent of the premium paid. Under the NAIC's Standard Nonforfeiture Law for Individual Deferred Annuities (Model 805, as amended in Fall 2020), which states adopt in their own form, the minimum rate used for those guaranteed values is tied to a five-year Treasury rate and set no higher than 3 percent and no lower than 0.15 percent, so ask what your own contract guarantees. Losses can still come from surrender charges and taxes on early withdrawals.

RILAs, Investor.gov explains, can lose money: if the index performs poorly, the insurer may deduct from your contract value, within limits the contract sets. The SEC's 2020 bulletin describes the two common limits:

• Floor: caps your loss at a set percentage. With a 10% floor and a 12% index drop, you lose 10%.
• Buffer (or shield): the insurer absorbs losses up to a set percentage first. With a 10% buffer and a 12% index drop, you lose 2%.

In both cases the bulletin notes the figures come before other adjustments such as surrender charges. In return for that protection, FINRA says, RILAs cap upside potential.

These numbers can change

The rate you see at purchase is often not the rate you keep. The SEC's 2020 bulletin says indexed annuity contracts commonly allow the insurer to change some features periodically, such as the rate cap, and that changes can affect your return. FINRA's 2022 article says the same about fees, participation rates and caps.

The NAIC's Annuity Disclosure Model Regulation (2021 edition) calls for illustrations of fixed indexed annuities to include a statement that includes, in substance: "It is likely that the index will not repeat historical performance, the non-guaranteed elements will change, and actual values will be higher or lower than those in this illustration but will not be less than the minimum guarantees." Treat any illustration built on past index performance as a scenario, not a forecast.

Questions to ask before you buy

• Which index does each option track, and does the credit include dividends?
• What are the current cap, participation rate and spread for each option?
• What are the guaranteed minimum cap and participation rate, and the guaranteed maximum spread, if any?
• How often can the insurer reset them, and how will I be notified?
• What is the crediting method and term length?
• What happens to interest if I withdraw in the middle of a term?
• For a RILA: is the protection a floor or a buffer, and at what level?

Key takeaways

• Indexed credits usually exclude dividends and pass through only part of the index's gain.
• Participation rates, caps and spreads each trim the credit, and they can be combined.
• Fixed indexed annuities generally guarantee a credit no lower than zero; RILAs can lose money within a floor or buffer.
• Insurers can commonly change caps, participation rates and spreads after purchase, so ask for the guaranteed limits.
• Illustrations based on past index performance are not guarantees or estimates of future results.

Sources

• SEC Office of Investor Education and Advocacy, Updated Investor Bulletin: Indexed Annuities (July 31, 2020)
• FINRA, The Complicated Risks and Rewards of Indexed Annuities (July 14, 2022)
• U.S. Securities and Exchange Commission (Investor.gov), Annuities
• National Association of Insurance Commissioners, Annuity Disclosure Model Regulation (Model 245, 2021)
• National Association of Insurance Commissioners, Standard Nonforfeiture Law for Individual Deferred Annuities (Model 805, Fall 2020)