Glossary term
Reinsurance
Reinsurance is insurance purchased by insurers to transfer part of their risk to another insurer or reinsurer.
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What Is Reinsurance?
Reinsurance is insurance for insurance companies. An insurer transfers part of its risk to another insurer, called a reinsurer, in exchange for premium. The original insurer remains responsible to its policyholders, while reinsurance helps manage large losses, volatility, capital strain, and concentration risk.
Reinsurance is one of the main reasons insurers can cover risks that would be too large or uneven to hold entirely on their own balance sheets. It sits behind the scenes, but it affects insurer capacity, pricing, catastrophe resilience, and financial stability.
Key Takeaways
- Reinsurance transfers part of an insurer's risk to a reinsurer.
- The policyholder usually continues dealing with the original insurer.
- Reinsurance can help insurers manage catastrophic losses, capital needs, and claim volatility.
- Common structures include treaty reinsurance and facultative reinsurance.
How Reinsurance Works
An insurer writes policies for customers and then cedes some portion of the risk to a reinsurer. The reinsurer receives premium and agrees to reimburse the insurer according to the reinsurance contract. The arrangement can apply to a portfolio of policies, a specific line of business, a catastrophe layer, or an individual large risk.
Reinsurance can be proportional, where the insurer and reinsurer share premiums and losses by percentage, or nonproportional, where the reinsurer pays losses above a defined threshold. Catastrophe reinsurance often works in layers, with different reinsurers taking different parts of the loss stack.
Common Reinsurance Structures
Structure | How it works | Typical use |
|---|---|---|
Treaty reinsurance | Covers a defined book or class of business | Ongoing portfolio risk management |
Facultative reinsurance | Covers an individual risk | Large or unusual policies |
Quota share | Premiums and losses shared by percentage | Capital support and growth capacity |
Excess of loss | Reinsurer pays above a retention level | Catastrophe or large-loss protection |
How It Affects the Insurance Market
Reinsurance pricing can influence the price and availability of insurance, especially in catastrophe-exposed markets such as homeowners, flood, wildfire, hurricane, and commercial property coverage. If reinsurers raise prices or reduce capacity, primary insurers may raise premiums, reduce limits, withdraw from certain areas, or tighten underwriting.
Reinsurance also creates counterparty risk. A primary insurer may expect reimbursement from a reinsurer after a large loss, but that protection depends on the contract and the reinsurer's ability to pay. Regulators and rating agencies watch reinsurance programs because they affect solvency, liquidity, and exposure concentration.
What It Means for Policyholders
Most policyholders never file a claim with a reinsurer. Their contract is with the primary insurer. Still, reinsurance can affect whether insurers are willing to write coverage in high-risk areas, how much capacity they can offer, and how they recover after disasters. A stressed reinsurance market can feed into premium increases or tighter underwriting for consumers and businesses.
The Bottom Line
Reinsurance is the risk-transfer system that helps insurers absorb large, concentrated, or volatile losses. It does not replace the policyholder's insurer, but it helps determine how much risk the insurance market can carry.