IAIS Insurance Capital Standard: 2026 Assessment Puts US Aggregation Method to a Global Test

From monitoring IAIS working group outputs and NAIC committee responses over the past 18 months, the gap between the global Insurance Capital Standard and the US aggregation method proposal remains wider than official communications suggest. On December 5, 2024, the International Association of Insurance Supervisors adopted the ICS as a prescribed capital requirement at its Annual General Meeting in Cape Town, closing a development cycle that began in 2013. The standard creates the first global risk-based capital measure calibrated to a 99.5 percent value-at-risk over a one-year time horizon, applying to 61 designated Internationally Active Insurance Groups across 19 jurisdictions. The IAIS published its 2026-2027 Roadmap in January 2026, confirming that member jurisdictions must complete a baseline self-assessment of their implementation progress this year, with targeted jurisdictional reviews beginning in 2027. For US multinationals including AIG, Chubb, MetLife, and Prudential Financial, the central question is whether the NAIC's aggregation method will satisfy IAIS comparability requirements or create a persistent dual-track compliance burden.

From Financial Crisis to Global Standard: A Decade of Development

The ICS grew out of post-crisis recognition that insurance group supervision lacked a common quantitative framework. The IAIS began formal development in 2013 as part of ComFrame, the Common Framework for the Supervision of Internationally Active Insurance Groups. ICS Version 2.0 was adopted in 2019 and entered a five-year confidential monitoring period from 2020 through 2024. During this period, participating IAIGs reported ICS data to their group-wide supervisors, but the results were never used to trigger supervisory action. The monitoring period generated thousands of data points on how the ICS performed across different group structures, product mixes, and jurisdictional contexts.

The November 14, 2024 decision by the IAIS Executive Committee approved the ICS for formal adoption and simultaneously concluded the Aggregation Method comparability assessment, finding that the US approach "provides a basis for implementation of the ICS to produce comparable outcomes." Three weeks later, on December 5, the full IAIS membership voted to adopt the standard alongside targeted updates to Insurance Core Principles in three areas: climate risk in investments and enterprise risk management, recovery and resolution enhancements, and valuation and capital adequacy revisions.

Technical Architecture: How the ICS Measures Capital

The ICS is built on three interconnected components that together produce a single group-level solvency ratio.

Market-Adjusted Valuation (MAV). The ICS constructs a consolidated group balance sheet using market-adjusted values derived from audited GAAP or statutory accounts. Insurance liabilities are measured as a current estimate (the probability-weighted average of the present value of future cash flows) plus a Margin Over Current Estimate (MOCE). The discount rate methodology uses a three-bucket approach, classifying liabilities into General, Middle, and Top buckets based on liability characteristics and backing asset profiles. Each bucket receives different yield curve adjustments designed to mitigate excessive volatility from extreme credit spread movements. The IAIS publishes prescribed yield curves for the 35 most traded currencies. Skadden's March 2025 analysis called the discount rate methodology "one of the most significant drivers of ICS results," noting that small calibration changes can produce significant swings in reported capital positions.

ICS Capital Requirement. The capital requirement is calibrated to a 99.5 percent value-at-risk over a one-year time horizon, a target criterion shared with Solvency II. The requirement aggregates charges across four risk categories: insurance risk, market risk, credit risk, and operational risk. Market risk sub-categories include interest rate risk, equity risk, real estate risk, currency risk, non-default spread risk, and asset concentration risk. Individual risk charges are aggregated using correlation matrices that recognize diversification benefits. Two measurement approaches apply depending on the risk: a stress approach (measuring the difference in capital resources before and after an instantaneous stress) and a factor-based approach (applying factors that reflect the capital requirement at different stress levels).

Qualifying Capital Resources (QCR). Capital resources are segregated into two tiers based on loss-absorption capacity and availability. Tier 1 capital represents the highest quality resources; Tier 1 Limited and Tier 2 capital face maximum percentage limits relative to the ICS capital requirement. The ICS ratio is calculated as QCR divided by the ICS capital requirement.

The Updated IAIG Register: 61 Groups, 19 Jurisdictions

The IAIS identifies IAIGs using a two-part test. A group must be internationally active, meaning it writes premiums in three or more jurisdictions with at least 10 percent of gross written premium outside the home jurisdiction. It must also meet a size threshold: total assets of at least USD 50 billion or total gross written premium of at least USD 10 billion, based on a three-year rolling average.

As of the September 2025 IAIS register update, 61 groups meet these criteria across 19 jurisdictions, up from the 59 IAIGs across 18 jurisdictions cited in most 2024 commentary. US-based IAIGs include AIG, Berkshire Hathaway, Chubb, CNA Financial, Liberty Mutual, MetLife, Prudential Financial, and Reinsurance Group of America. European groups include Allianz, AXA, Generali, Aegon, Munich Re, Hannover Re, and SCOR. Japanese IAIGs include Nippon Life, Dai-ichi Life, Tokio Marine, Sompo Holdings, and MS&AD. The full register spans Switzerland, Canada, Australia, Bermuda, China, Korea, and several additional markets.

The 2026-2027 Roadmap: From Baseline to Jurisdictional Review

The IAIS published its 2026-2027 Roadmap in January 2026, setting out a three-phase implementation sequence. During 2025, the IAIS developed the detailed ICS implementation assessment methodology, publishing high-level principles for the assessment in July 2025. In early 2026, IAIS members receive a structured self-assessment questionnaire covering the legal basis for ICS implementation, the scope of group supervision, valuation and capital requirement methodology, governance and supervisory review processes, and transitional arrangements. Jurisdictions respond on a prescribed timeline running through the second half of 2026, and the IAIS Secretariat aggregates the responses into a baseline report.

Beginning in 2027, the IAIS conducts targeted jurisdictional assessments using smaller supervisory teams, site visits, and detailed review of selected IAIG group supervisory files. The output is a set of findings and recommendations, both jurisdiction-specific and thematic, that feed into the IAIS Implementation and Assessment Committee work plan. As we detailed in our analysis of the baseline self-assessment mechanics, the 2026 exercise is the reference point against which 2027's deeper jurisdictional scrutiny is calibrated.

A critical caveat: the IAIS does not have legal authority to mandate implementation into jurisdictional legislation. Member supervisors are committed to implementing IAIS standards while adapting them to local market circumstances. The practical consequence is that implementation timelines, transition arrangements, and scope decisions vary across jurisdictions, creating the heterogeneity that the assessment process is designed to surface and address.

The US Position: NAIC Aggregation Method and the Comparability Determination

The US did not adopt the ICS directly. Instead, the NAIC developed the Aggregation Method as a domestic alternative, building on the existing state-level Risk-Based Capital framework aggregated across the insurance group. The November 2024 IAIS comparability finding stated that the AM "provides a basis for implementation of the ICS to produce comparable outcomes." Sullivan & Cromwell's December 2024 memo confirmed that US-based IAIGs will not be required to implement the ICS as a prescribed capital requirement; they will use the Aggregation Method instead.

The NAIC created the Aggregation Method Implementation (G) Working Group in early 2025 to manage the domestic transition. At the Spring 2026 National Meeting on March 23, the AMIWG discussed a draft outline of its Review of US Group Solvency Regulation, covering the sensitivity of group capital to interest rate changes, supervisory intervention mechanisms, the use of Excess Relative Ratio scalars calibrated at 200 percent of the NAIC RBC Authorized Control Level, and reporting and disclosure requirements. On the last point, no consensus has been reached on reconciling the AM's public disclosure obligations with the Group Capital Calculation's existing confidentiality restrictions. This is a substantive structural question: the ICS requires public disclosure of group capital positions, while the GCC results that feed the AM are currently treated as confidential supervisory information.

The working group's target timeline calls for a draft AM by mid-2026, with a final version by 2027 or later and implementation targeted at 2027 at the earliest. Any recommendations requiring changes to the GCC or ORSA frameworks are referred to the Financial Condition (E) Committee, with updates to documentation expected in the second half of 2026.

Two Flagged Gaps: Interest Rate Risk and Supervisory Intervention Timing

The November 2024 comparability finding was not unconditional. The IAIS flagged two specific areas requiring further work: the treatment of interest rate risk and the timing of supervisory intervention.

The interest rate risk gap reflects a structural difference in how the ICS and the AM treat long-duration life insurance liabilities. The ICS applies its MAV framework with prescribed discount curves, producing a market-consistent view of liability sensitivity to interest rate movements. The AM inherits the US statutory reserving framework, where cash flow testing under ASOP No. 7 and the mechanics of principle-based reserving produce a different set of discount rate dynamics. The monitoring period data showed that the two approaches can produce materially different capital sensitivity profiles for the same life insurance block, particularly during periods of rapid rate movement. This is not a question of which approach is "right"; it is a question of whether the magnitude of the difference is small enough to fall within the IAIS's definition of comparable outcomes.

The supervisory intervention gap concerns the timing and triggers for regulatory action on group capital grounds. The ICS prescribes a solvency control level below which supervisors must intervene. The US system operates through state-level RBC action levels at the entity level, with group-level intervention tools that are more consultative than prescriptive. The IAIS has asked whether the AM's supervisory response framework produces intervention at comparable points relative to the ICS trigger, or whether the US approach permits larger erosion of group capital before mandatory action begins.

Europe's Solvency II Head Start

European carriers enter the ICS implementation with a structural advantage. Solvency II already provides a market-consistent group capital framework calibrated to the same 99.5 percent VaR target criterion as the ICS. The revised Solvency II Directive (Directive 2025/2), adopted in November 2024 and requiring member state transposition by January 30, 2027, introduced tougher spread-risk stress tests, new extrapolation formulas for long-term liabilities, revised risk margin methodology, enhanced treatment of long-term equity investments, and mandatory integration of climate and sustainability risks.

EIOPA stated in November 2024 that it "stands ready to collaborate closely with the IAIS and its members to ensure a smooth transition to the new ICS standard." The practical implication is that EEA IAIGs, including Allianz, AXA, Generali, and Aegon, already report under a framework that is architecturally aligned with the ICS. Their self-assessment responses will document how Solvency II maps to ICS requirements, with most dimensions showing close alignment. The reporting infrastructure exists; the implementation assessment for EEA jurisdictions is largely a mapping exercise rather than a framework-building exercise.

Insurance Europe, the industry body, has taken a firmer position. It supports the ICS "as long as it results in a measurement framework that correctly captures insurers' risks and long-term business and is a single standard applied widely and in all key insurance markets globally." Insurance Europe has set three explicit conditions: internal models must be a permanent part of the ICS framework, all major jurisdictions must commit to consistent implementation, and the reviewed Solvency II framework should become the EU's implementation of the ICS, avoiding what it describes as "the unacceptable situation of EU (re)insurers having to run their business under two prudential regimes." That third condition carries real weight. If the ICS produces requirements that diverge materially from Solvency II even after the 2024 revisions, European carriers and their supervisors will resist layering an additional regime on top of the existing one.

Comparison: ICS, Aggregation Method, and Solvency II

Feature	ICS	US Aggregation Method	Solvency II
Calibration target	99.5% VaR, 1-year	Comparable outcomes via ERR scalars at 200% ACL	99.5% VaR, 1-year
Valuation basis	Market-adjusted (MAV)	US statutory (SAP) aggregated across group	Market-consistent (best estimate + risk margin)
Group-level scope	Consolidated group balance sheet	Aggregation of solo-entity RBC positions	Consolidated group balance sheet
Structured credit treatment	Look-through to underlying collateral	NAIC designation-based factors (SVO/NRSRO ratings)	Look-through with spread risk stresses
Affiliated reinsurance	Consolidated; intra-group eliminated	Entity-level cession reflected, then aggregated	Consolidated; intra-group eliminated
Disclosure	Public group capital disclosure required	GCC results currently confidential	Public SFCR and QRT disclosures
Internal models	Permitted for certain risk categories	Not applicable (factor-based)	Full and partial internal models permitted

The table surfaces a pattern: on most structural features, the ICS and Solvency II are aligned, while the AM diverges on valuation basis, group-level aggregation mechanics, and disclosure. This alignment is not coincidental. The ICS was built with Solvency II as a reference architecture, and the shared 99.5 percent VaR target criterion reflects that lineage.

The Federal Reserve's November 2024 Warning on Long-Term Products

On November 13, 2024, one day before the IAIS Executive Committee approved the ICS, the Federal Reserve published its ICS Impact Report as required by Section 211(c)(3)(A) of the Economic Growth, Regulatory Relief, and Consumer Protection Act. The report's central finding is that IAIGs subject to the ICS "would likely be economically pressured to reduce or stop the sale of long-term products," pass additional capital-associated costs to consumers, or change product offerings. This concern applies primarily to life and annuity writers, where the ICS's market-consistent liability valuation and prescribed discount curves produce different capital requirements than the US statutory framework that currently governs these products.

For P&C-focused groups, the Federal Reserve's analysis found a more favorable outcome. P&C groups' capital resource levels "benefit under ICS" due to differences in reserve valuation between US statutory accounting and the ICS market-adjusted approach. The shorter-duration liability profiles of most P&C lines interact differently with the MAV framework than long-duration life and annuity blocks.

This directional split is important for understanding why the AM's comparability was assessed favorably at the headline level while producing persistent divergences on specific product lines. The AM's aggregation of US statutory positions tends to produce a more conservative view for P&C groups and a less conservative view for life groups, relative to the ICS. The 2026 self-assessment will surface this product-line asymmetry in structured supervisory data for the first time.

ICS Meets Active NAIC Reform Workstreams

The ICS does not exist in isolation from the domestic regulatory changes already underway. Several active NAIC workstreams interact directly with the AM's ability to demonstrate comparable outcomes.

CLO capital charge recalibration. The Academy of Actuaries proposed C-1 risk factors ranging from 0.03 percent to 2.73 percent for investment-grade CLO tranches and 12.59 percent to 70.82 percent for below-investment-grade tranches, with a tranche thickness adjustment that sharply increases charges for thin junior positions. As we analyzed in our CLO capital overhaul coverage, these factors bring the US treatment of structured credit meaningfully closer to the ICS's look-through approach. No changes were adopted at the Spring 2026 meeting; any changes take effect for RBC reporting as of December 31, 2026.

RBC governance framework overhaul. The Model Governance Task Force's nine-principle framework establishes systematic governance for how RBC factors evolve, with the "Equal Capital for Equal Risk" principle directly echoing ICS philosophy. A systematic governance framework strengthens the US position in comparability discussions by demonstrating that state-based RBC is actively maintained rather than resistant to change.

Investment subsidiary RBC elimination. The April 2026 exposure deleting the investment subsidiary category from RBC formulas across life, P&C, and health is structurally aligned with the ICS's consolidated group view, which looks through investment holding structures rather than applying a blanket subsidiary charge.

IAIS structural shifts in life insurance. In November 2025, the IAIS published an Issues Paper on structural shifts in the life insurance sector, concluding that systemic risk "appears limited at the global aggregated level" while noting that the rapid growth of alternative assets and asset-intensive reinsurance "warrant close monitoring." The paper introduced a globally agreed principles-based classification of alternative assets, creating a consistent lens through which supervisors evaluate the complex structures that the IAIS FundedRe workstream is simultaneously addressing. For PE-backed life insurers, where the NAIC adopted a 45 percent RBC charge for residual tranches in all structured securities in 2024, the ICS's MAV approach and the NAIC's factor-based approach are converging toward similar prudential outcomes through different technical paths.

The Dual-Track Compliance Burden for US Groups

Although the AM comparability finding means US IAIGs are not required to adopt the ICS directly, the practical compliance picture is more complex than a simple either/or. US carriers operating subsidiaries in ICS-implementing jurisdictions face local requirements from host supervisors. The ICS is a group-wide, consolidated standard; it does not replace entity-level requirements. US IAIGs must still comply with state-level RBC at the entity level, the Federal Reserve's Building Block Approach for Fed-supervised insurance organizations, and potentially the ICS for non-US subsidiaries operating in jurisdictions that implement the standard directly.

From tracking actuarial staffing requirements at IAIGs that participated in the monitoring period, the resource burden of running parallel capital frameworks is substantial. Building and maintaining the reconciliation between AM and ICS reference capital requires actuaries who understand both the US statutory framework and the market-consistent valuation approach, a combination that is not common in existing actuarial teams. The discount rate sensitivity analysis alone, where small changes in the three-bucket methodology produce large swings in liability values, requires dedicated modeling resources that most US groups did not budget for before the ICS became a live supervisory tool.

The EIOPA reporting reforms taking effect in 2027 offer a useful counterpoint. While European regulators are cutting 26 percent of quarterly reporting templates to reduce compliance burden, the ICS implementation is adding reporting requirements for US groups. The net effect is that European IAIGs' compliance costs may decrease while US IAIGs' costs increase, an asymmetry that will factor into competitive dynamics in cross-border markets.

Why This Matters for Actuaries

The ICS is not merely a regulatory compliance exercise. It reshapes the capital lens through which group-level strategic decisions are evaluated. Product pricing, reinsurance structure, asset allocation, and M&A due diligence all feed into or from the group capital position. When the capital framework shifts from a pure statutory aggregation to one that must also be reconciled against a market-consistent global reference, the actuarial function becomes the natural integration point.

Three specific demands fall on the actuarial team. First, liability valuation under the MAV framework requires modeling capabilities that extend beyond traditional statutory reserving. The three-bucket discount rate approach, the MOCE calculation, and the current-estimate methodology all require actuaries to build and maintain parallel projection models. Second, the correlation matrices used in the ICS capital aggregation create diversification credit calculations that differ from RBC's covariance-based approach, requiring separate documentation of the risk aggregation methodology. Third, the self-assessment and subsequent jurisdictional reviews will generate supervisory questions that actuaries at IAIGs need to answer with quantitative precision rather than qualitative narratives.

For actuaries at non-IAIG carriers, the ICS is still relevant as a directional signal. The NAIC's domestic reforms, from CLO capital charges to the RBC governance framework to the investment subsidiary elimination, are being calibrated with an eye toward ICS comparability. The factor updates that land on every US insurer's RBC filing are shaped, in part, by the need to demonstrate that the state-based system produces outcomes comparable to the global standard.

The Bottom Line

The IAIS Insurance Capital Standard is the first global solvency framework for insurance groups, calibrated to a 99.5 percent VaR standard and applying to 61 IAIGs across 19 jurisdictions. The 2026 baseline self-assessment is where the theoretical comparable-outcomes claim begins carrying quantitative weight. European carriers enter the process with Solvency II alignment providing a structural head start. US carriers face the more complex task of demonstrating that an aggregation of entity-level statutory positions produces outcomes comparable to a consolidated market-consistent framework, while simultaneously managing two flagged gaps in interest rate risk treatment and supervisory intervention timing. The NAIC's active reform agenda is closing the distance, but the gap is not yet closed, and the 2027 jurisdictional assessments will examine the residual divergence under supervisory scrutiny. For actuaries, the ICS creates concrete modeling, reconciliation, and governance demands that will shape group capital work for the next several years.