Reinsurance sits behind many policies that consumers and companies buy, even though the policyholder may never interact with the reinsurer. It is one of the systems that allows an insurer to write more risk than it would comfortably retain on its own balance sheet.
The NAIC describes reinsurance as a contract in which an insurer — the cedent — transfers all or part of one or more risks to a reinsurer. Reinsurers can themselves buy reinsurance, known as retrocession.
Why insurers buy reinsurance
- Catastrophe protection: to limit the effect of one hurricane, earthquake, wildfire or other accumulation event.
- Capital management: to shape the amount and volatility of risk retained.
- Capacity: to support larger limits or more policies than the insurer could safely retain alone.
- Portfolio stabilization: to reduce earnings volatility from unexpectedly large claims.
- Specialist expertise: in some cases, reinsurers contribute technical knowledge, analytics and product support.
Treaty vs. facultative reinsurance
Treaty reinsurance covers a defined portfolio or class of business under a standing agreement. Risks that meet the treaty terms are ceded according to the contract. Facultative reinsurance is arranged for an individual risk or policy and is separately underwritten by the reinsurer.
Proportional vs. non-proportional structures
| Structure | How it works | Typical objective |
|---|---|---|
| Quota share | Insurer and reinsurer share premiums and losses in an agreed percentage | Capital support and portfolio sharing |
| Surplus | Shares risks above the insurer’s chosen retention, subject to treaty capacity | Manage larger sums insured |
| Per-risk excess of loss | Reinsurer pays covered loss above a retention on an individual risk | Limit severity of large claims |
| Catastrophe excess of loss | Responds when aggregate losses from a defined event exceed a retention | Protect against accumulation events |
A simple catastrophe example
Imagine an insurer has a catastrophe reinsurance layer that attaches after $100 million of covered losses from a qualifying event and provides $200 million of limit. If an event produces $250 million of covered losses within the contract definition, the insurer retains the first $100 million and the reinsurance layer can respond to the next $150 million, subject to all terms and recoverability.
The example is intentionally simplified. Real programs can contain multiple layers, reinstatements, occurrence definitions, exclusions and aggregate features.
Why reinsurance pricing matters to consumers
Reinsurance is part of the cost structure of primary insurance, especially for catastrophe-exposed property. When reinsurance becomes more expensive or scarce, primary insurers may change rates, limits, deductibles, underwriting appetite or the amount of business they are willing to write in exposed areas. Reinsurance is not the only driver of retail prices, but it can influence market capacity.
What is retrocession?
A reinsurer may decide that it does not want to retain all the risks it has accepted from insurers. It can transfer part of those risks to another reinsurer or capital provider. That second transfer is known as retrocession. The result is a global network through which catastrophe and other insurance risks can be distributed across multiple balance sheets and capital sources.
Reinsurance and insurance-linked securities
Traditional reinsurers are not the only providers of catastrophe capacity. Insurance-linked securities, including catastrophe bonds, can transfer defined insurance risks to capital-market investors. These instruments have different triggers and structures but serve a related objective: bringing additional risk-bearing capital into the insurance system.
Frequently asked questions
Does reinsurance mean the original insurer no longer owes the policyholder?
Generally, no. The policyholder’s contract remains with the primary insurer. Reinsurance is a separate contract between the insurer and reinsurer.
What is a reinsurance broker?
A reinsurance broker helps insurers structure and place reinsurance programs with reinsurers and capital providers.
Can reinsurers fail?
Yes. Reinsurance introduces counterparty credit risk, which is why insurers and regulators pay attention to reinsurer financial strength, collateral and diversification.
Sources & further reading
This explainer simplifies technical structures. Actual reinsurance contracts are negotiated documents with detailed definitions and conditions.
