Surplus reinsurance is a proportional treaty under which the ceding company keeps a stated line and cedes the surplus above that retention, subject to treaty limits.
Why It Matters
Surplus reinsurance helps explain how insurers can write larger individual risks without retaining the full amount on their own books. It is especially useful when risk sizes vary and a fixed percentage on every policy is not the best fit.
How It Works in Real U.S. Insurance Practice
The ceding company retains a fixed amount, often called a line, and cedes the amount above that line up to the treaty capacity. Premium and losses are then shared proportionally based on how much of the risk was ceded. This makes surplus reinsurance a form of pro rata reinsurance, but one driven by retained amount rather than a flat percentage on every policy.
Surplus treaties are often used in property and other lines where insured values differ significantly from one account to another.
Practical Example
If an insurer retains the first $500,000 on each qualifying property risk and cedes the amount above that level up to treaty capacity, the ceded percentage will vary from policy to policy depending on the size of the insured value.
Common Misunderstandings or Close Contrasts
- Surplus reinsurance is proportional, not excess-of-loss.
- It differs from quota share because the ceded percentage can vary by risk size.
- The ceding company’s retained line stays central to how the treaty operates.