An insurer reports $120 million of surplus and calls itself well capitalized. A regulator asks a sharper question: well capitalized relative to what risks? Risk-based capital answers by sizing required capital to the company's own asset and underwriting risk, then comparing it to what the company actually holds.
A flat minimum capital rule treats a tiny homeowners writer and a large workers' compensation writer the same. That is wrong. Risk-based capital instead builds a required amount from the company's actual exposure. More volatile reserves, riskier assets, and thinner reinsurance security all raise the requirement.
KEY: RBC is a solvency floor, not a target. A ratio comfortably above 200% is normal and expected. RBC only flags companies whose capital is thin relative to their risk.
The formula applies factors to balance-sheet and premium items, grouping the results into risk categories. Each captures one family of risk.
R0. Affiliated and off-balance-sheet risk. Investments in insurance subsidiaries and off-balance-sheet items such as guarantees and non-controlled assets. R0 sits outside the square root, so it is never diversified away.
Common mistakes
- Adding the charges arithmetically. Summing R0 through Rcat straight gives $188M in Example 1, not $89.35M. You must square R1 through Rcat, add, take the root, then add R0. Skipping the covariance overstates required capital by more than double.
- Putting R0 inside the square root. Affiliate and off-balance-sheet risk is added outside the root. Folding it in understates required capital.
- Dropping Rcat or the operational risk add-on. Rcat (2017) belongs inside the root as a squared term. Basic operational risk (2018) is a 3% add-on applied after covariance, and ACL is half of the total including that add-on. Halving the bare covariance result understates ACL.
Bottom line
- The P&C RBC formula has eight risk categories: R0 (affiliates and off-balance-sheet), R1 (fixed-income asset risk), R2 (equity asset risk), R3 (credit/reinsurance recoverable risk), R4 (loss and LAE reserve risk), R5 (net written premium risk), Rcat (catastrophe risk, added 2017)...
- LAE is the cost of investigating, defending, and settling claims, so RBC charges it alongside the loss itself.
- The covariance adjustment combines R1 through Rcat by the square root of the sum of their squares, then adds R0 outside the root.
- Operational risk is a 3% add-on applied after covariance. Authorized Control Level (ACL) RBC equals 50% of the Total RBC After Covariance including Basic Operational Risk.
Exam shortcut
Compute in a fixed order every time: square R1 through R5 and Rcat, sum, square-root, add R0, apply the 3% operational risk add-on, halve to get ACL RBC, then divide TAC by ACL RBC. A misplaced R0, a dropped Rcat, or a skipped halving is the most common lost point. Memorize the four thresholds as 200-150-100-70.
The full lesson (about 3,639 words, 24 min read) adds 2 worked examples, all 7 common mistakes, a self-check, free in the app.
Learning objectives
- C3
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