Excess of Loss
Non-proportional reinsurance where the reinsurer pays losses that exceed a specified retention amount retained by the cedent.
What It Is
Excess of loss (XOL) is a non-proportional form of reinsurance where the reinsurer indemnifies the cedent for losses that exceed a specified retention (attachment point) up to a specified limit. Unlike proportional treaties where every loss is shared, excess of loss only triggers when losses breach the retention threshold. The cedent retains all losses below the attachment point.
Excess of loss treaties come in several varieties. Per-risk XOL protects against large individual losses on single risks. Per-occurrence XOL (also called catastrophe XOL) protects against accumulation of losses from a single event affecting multiple risks. Aggregate XOL (also called stop loss) protects against the cumulative total of losses over a period exceeding a threshold.
Pricing for XOL is based on expected losses in the layer (between the attachment point and the limit), historical loss frequency and severity at those levels, and the cedent's risk profile. Because XOL typically covers low-frequency, high-severity events, the premium is usually a small percentage of the coverage provided. A $10M XOL excess of $5M might cost 2-5% of the limit, or $200,000-$500,000.
Why It Matters for Brokers
Excess of loss reinsurance directly influences how carriers manage catastrophe exposure and individual large-loss risk. When XOL rates increase at treaty renewal, carriers face higher costs to maintain the same level of protection, and these costs flow through to policyholders as rate increases. Understanding XOL dynamics helps brokers explain market-wide rate movements to clients.
Real-World Example
A carrier has a per-occurrence catastrophe XOL treaty of $50M excess of $10M. A hurricane causes $35M in covered losses across the carrier's book. The carrier retains the first $10M and recovers $25M from the reinsurer. Without the treaty, the $35M loss would have severely impacted the carrier's surplus. At the next treaty renewal, the reinsurer increases the rate-on-line from 8% to 12%, adding $2M to the carrier's annual reinsurance cost, which contributes to a 4% property rate increase across the carrier's portfolio.
Common Mistakes
- 1Not connecting carrier rate increases to reinsurance cost increases, which are often the primary driver of market-wide hardening in catastrophe-exposed lines.
- 2Misunderstanding that carrier per-occurrence limits are often defined by the excess of loss treaty structure, not by individual policy terms.
How brokerageaudit.com Handles This
brokerageaudit.com monitors reinsurance market conditions and incorporates this context into rate change analyses, helping brokers explain to clients why carrier-level rate actions are driven by reinsurance economics rather than individual account performance.