From reviewing IAIS comparability assessments since the 2019 Kuala Lumpur agreement, the US Aggregation Method represents the most consequential shift in group capital regulation since the Group Capital Calculation was first introduced. The NAIC's Aggregation Method Implementation (G) Working Group, now chaired by Acting Chair Rebecca Easland of Wisconsin, exposed its draft "Review of US Group Solvency Regulation and Implementation of the ICS via the AM" at the Spring 2026 National Meeting in San Diego on March 23. The 45-day public comment period closes May 11, 2026, with comments directed to NAIC Senior Advisor Ned Tyrrell. What follows is the final window for industry input on a framework that will define US group capital regulation for internationally active insurance groups for years to come.

The draft review's central conclusion is striking in its restraint: "Implementation of the AM can be achieved primarily through targeted refinements to existing U.S. regulatory tools rather than the creation of a new framework." This signals that the NAIC intends to preserve the state-based regulatory architecture rather than layering on a parallel solvency system. But targeted refinements to an existing framework can still carry substantial operational consequences, and the four areas under review touch core assumptions about how group capital adequacy is measured, disclosed, and enforced.

The Decade-Long Road to Comparability

Understanding why this comment period matters requires tracing the global capital standards debate back to its origins. The 2008 financial crisis exposed gaps in group-level supervision of internationally active insurers. AIG's near-collapse demonstrated that entity-level solvency could mask group-wide liquidity and capital concentration risks. The Financial Stability Board responded in 2013 by directing the International Association of Insurance Supervisors (IAIS) to develop a comprehensive supervisory framework for internationally active insurance groups, including quantitative capital standards.

The IAIS spent the next decade building the Insurance Capital Standard (ICS): a group-wide consolidated approach using Market-Adjusted Valuation with prescribed yield curves, a uniform Tier 1/Tier 2 capital resource classification, and a single prescribed formula calibrated at 99.5% Value at Risk over a one-year time horizon. Four consultations, six field-testing exercises, and five years of confidential monitoring culminated in formal ICS adoption on December 5, 2024, at the IAIS Annual General Meeting in Cape Town.

The US, however, never accepted the premise that a single global capital formula should supersede jurisdiction-level standards. The state-based RBC system, the NAIC argued, already captures risks through a combination of statutory reserve requirements and capital charges. Different jurisdictions emphasize reserves and capital in different proportions, and forcing a uniform valuation approach would disrupt well-functioning regulatory regimes without clear solvency benefits.

This disagreement produced the "unified path to convergence" agreed at the November 2019 IAIS meeting in Kuala Lumpur. Rather than requiring full ICS adoption, the IAIS would assess whether an alternative approach, the US Aggregation Method, produces comparable outcomes to the ICS. The comparability assessment framework was formalized in stages: definition of comparable outcomes and six high-level principles in March 2021, final comparability criteria in March 2023, and a provisional AM published by the NAIC in September 2023 for assessment purposes.

On November 14, 2024, the IAIS Executive Committee concluded that the US Aggregation Method "provides a basis for implementation of the ICS to produce comparable outcomes." IAIS Executive Committee Chair Shigeru Ariizumi called the ICS adoption "a landmark achievement." The assessment was based on data collected from nine US-based IAIGs and one US non-life non-IAIG volunteer group. But the Executive Committee flagged two specific areas requiring convergence work: treatment of interest rate risk and appropriate timing of supervisory intervention. Those two flagged areas directly inform the draft review now open for comment.

How Aggregation Differs From Full ICS

The philosophical difference is fundamental. The ICS starts at the group level and works down; the Aggregation Method starts at the legal entity level and works up. This distinction has profound implications for how capital adequacy is calculated, what data is required, and how supervisory intervention decisions are made.

Dimension Insurance Capital Standard US Aggregation Method
Calculation approach Group-wide consolidated from the outset Legal entity/subsidiary level, then aggregated to group
Valuation basis Market-Adjusted Valuation with IAIS-prescribed yield curves for 35 currencies Each jurisdiction's existing statutory/regulatory valuation
Capital resources Uniform Tier 1/Tier 2 classification; Tier 2 capped at 50% of requirement for non-mutuals Locally reported available capital with scalar adjustments
Capital requirement Single prescribed formula (99.5% VaR, one-year horizon) Aggregates local regime capital requirements via ERR scalars
Risk capture Four standardized risk charge categories: insurance, market, credit, operational Risks partly captured in capital requirement, partly in valuation; varies by jurisdiction
Liability classification Three-bucket system for discounting Uses local reserve methodologies
Jurisdiction treatment One standard applied uniformly across all IAIG jurisdictions Respects existing capital regimes; adjusts via scalars for cross-border comparability

The AM's design reflects a deliberate trade-off. By preserving existing jurisdiction-level standards, it avoids the cost and disruption of imposing a new valuation and capital regime on US insurers. The NAIC has described this as "less burdensome and costly to regulators and industry and respecting other jurisdictions' existing capital regimes." But it also means the AM inherits whatever limitations exist in the underlying entity-level standards, including the interest rate sensitivity gap that the IAIS flagged.

The Four Review Areas in Detail

1. Excess Relative Ratio Approach and Scalar Methodology

The ERR approach, adopted by the GCC (E) Working Group in July 2023, is the quantitative engine that makes cross-border aggregation work. It adjusts available and required capital for non-US insurance regimes to account for differences in calibration levels and valuation approaches across jurisdictions.

The calibration reference point is 200% of the NAIC Risk-Based Capital Authorized Control Level (ACL), which equals 100% Company Action Level (CAL) RBC. This is the first regulatory intervention threshold under the US system: at or above 200% ACL, no regulatory action is required. Below 200% ACL, interventions escalate from required action plans to regulatory takeover.

The ERR scalar calculation compares each jurisdiction's aggregate industry-wide capital to its first-intervention level. The excess capital above the intervention point is expressed as a ratio, and the scalar is calculated by dividing a foreign jurisdiction's excess capital ratio by the US excess capital ratio. NAIC materials illustrate with an example: if Country A's life insurer excess ratio is 54% and the US excess ratio is 385%, Country A's scalar equals 54% divided by 385%, or 14%. The GCC uses 200% ACL for the base calculation and 300% ACL for a sensitivity test, with three years of historical data used for calibration.

For actuaries working at groups with significant non-US operations, the scalar methodology determines how foreign subsidiary capital contributes to the group ratio. A scalar that underweights a well-capitalized foreign operation could trigger false alarm signals at the group level; a scalar that overweights it could mask genuine capital strain. The draft review's treatment of scalars will establish whether the current ERR calibration is sufficient or whether refinements are needed to achieve the "comparable outcomes" standard the IAIS requires.

2. Interest Rate Sensitivity of US Life Reserves

This is the area where the AM's reliance on existing US standards creates the most significant comparability challenge. US statutory life insurance reserves for long-duration products (whole life, traditional annuities, payout annuities) use prescribed interest rate assumptions that do not fully reflect current market rates. Under the ICS's Market-Adjusted Valuation approach, liabilities are revalued using current yield curves, making the ICS inherently responsive to interest rate movements.

The practical consequence: under a rapid rate decline scenario, the ICS would show an immediate increase in liability values (and corresponding capital strain) at the group level. The AM, relying on US statutory reserves with embedded conservatism in prescribed rates, would respond more slowly or not at all. In a rising rate environment, the reverse pattern emerges: the ICS would show liability relief that the AM's US component would not reflect at the same speed.

This divergence was one of two specific areas the IAIS flagged for convergence work. The draft review proposes enhanced GCC disclosures including interest rate sensitivity metrics and reserve composition transparency. These enhancements would not change how US reserves are calculated at the entity level, but they would provide group-level supervisors with the information needed to assess whether rate environment changes are creating hidden capital adequacy shifts that the AM's aggregate ratio does not capture.

For life actuaries at IAIGs, this means preparing to disaggregate reserve composition data in ways that current statutory reporting does not require. The GCC already includes eight sensitivity analyses, but the enhanced disclosures may require more granular breakdowns of how specific product blocks and reserve methodologies respond to rate stress scenarios.

3. Supervisory Intervention Tools

The third review area examines whether existing US supervisory tools provide adequate mechanisms for group-level capital intervention decisions. The draft review identifies the key existing tools:

The draft review's specific recommendation on intervention tools is notable: the ORSA guidance manual should be clarified to designate the GCC as the appropriate measure of regulatory capital at the IAIG head level. This connects the quantitative GCC output to the qualitative ORSA process, creating a defined pathway from capital measurement to supervisory action. Currently, the GCC exists as an analytical tool without explicit intervention triggers at the group level (unlike entity-level RBC, which has defined Company Action Level and Regulatory Action Level thresholds). The review proposes clarifying when and how group-level GCC results should inform supervisory intervention decisions.

The policy position embedded in this area is that no new supervisory framework is needed. Existing tools can be refined to meet AM and ICS requirements. This is consistent with the broader NAIC philosophy of building on the state-based system rather than creating parallel structures, but it places substantial weight on regulatory coordination across multiple states for multi-domiciliary groups.

4. Reporting and Disclosure Requirements

The fourth area is still under active development at the IAIS level. The IAIS Standards and Supervisory Practices Committee is developing ComFrame standards for ICP 9 (Supervisory Review and Reporting) and ICP 20 (Public Disclosure). The draft Solvency Regulation Review addresses "forthcoming ComFrame reporting and disclosure requirements in a manner consistent with the aggregation-based approach."

Proposed GCC reporting enhancements include interest rate sensitivity metrics, reserve composition data disaggregation, and transparency improvements designed to facilitate cross-border regulatory comparability. For groups already filing the GCC, these enhancements would expand the data requirements beyond the current template. For groups at the IAIG threshold, the enhanced reporting may represent a material new compliance obligation.

Which Groups Are Affected

The Aggregation Method and enhanced GCC requirements apply primarily to Internationally Active Insurance Groups. IAIG designation requires meeting two tests simultaneously: international activity (premiums written in three or more jurisdictions, with at least 10% of gross written premiums outside the home jurisdiction) and size (total assets of at least $50 billion or gross written premiums of at least $10 billion on a three-year rolling average).

As of the January 2026 IAIS register, 60 IAIGs have been identified across 19 jurisdictions, up from 49 IAIGs across 17 jurisdictions in July 2022. Named US IAIGs include AIG (supervised by NY DFS, operating in approximately 95 countries), MetLife (supervised by NY DFS, operating in approximately 50 countries), and Prudential Financial (operating in over 30 countries). All three were previously designated as Global Systemically Important Insurers by the Financial Stability Board. Additional US groups likely qualify based on size and international criteria, including Chubb and Berkshire Hathaway, though the full register is maintained by group-wide supervisors and updated annually.

Group-wide supervisors also retain discretion to designate additional groups as IAIGs based on "substantial insurance operations," even outside the standard size and activity criteria. New York's regulation (11 NYCRR Section 82.4(b)) explicitly provides for this discretionary designation. This means the scope of affected groups could expand beyond the current register without changes to the formal thresholds.

The GCC: Foundation of the Aggregation Method

The AM does not exist in isolation. It builds on the Group Capital Calculation, itself a product of the NAIC's Solvency Modernization Initiative launched in 2008 in response to the Great Recession. The GCC (E) Working Group was formed in early 2016, and the NAIC adopted the initial GCC Instructions and Template in December 2020, alongside revisions to the Insurance Holding Company System Regulatory Act (Model #440) and Model Regulation (Model #450).

The GCC works as a bottom-up calculation. Starting at the legal entity level, available and required capital are aggregated to the group level after eliminating intragroup transactions and double-counting. For US insurers, calculated capital "generally equals the result of the existing risk-based capital calculation." Non-US entities have their required capital converted via ERR scalar adjustments. The resulting Group Capital Ratio (Available Capital divided by Calculated Capital) provides the quantitative group solvency measure.

The AM is described by the NAIC as a "jurisdictionally agnostic approach to group capital that is influenced by, and calculated similarly to, the GCC" but designed for international comparability. The draft Solvency Regulation Review proposes the GCC as the operational mechanism through which AM results are generated. This means that refinements to the AM translate directly into changes to GCC filing requirements, and GCC filers at IAIG-qualifying groups should treat AM implementation as a direct extension of their existing GCC compliance obligations.

The GCC already evaluates eight sensitivity analyses to assess potential impacts on the capital ratio. Entity classification follows three categories: insurers, financial non-insurer entities, and non-insurer/non-financial entities. The scope follows the ultimate controlling person definition in Model #440, capturing the full holding company structure.

Post-Comment Timeline and Adoption Path

The comment period closing May 11 is just the beginning of a compressed review schedule:

Date Action Significance
May 11, 2026 Public comment period closes Final window for industry input on all four review areas
May 21, 2026 Regulator-only session to review exposure feedback Internal regulatory alignment before public discussion
June 2, 2026 Open call to discuss feedback and possible refinements Industry visibility into regulatory response to comments
June 11, 2026 Vote to approve updated draft Working Group action on revised review document
Summer 2026 Expected (G) Committee adoption at Summer National Meeting Formal adoption of the AM implementation framework
H2 2026 Recommendations requiring GCC/ORSA changes referred to Financial Condition (E) Committee Technical implementation phase begins
H2 2026 Updates to Final AM documentation Completion of the US implementation pathway

This timeline is ambitious. Between the May 11 comment deadline and the Summer National Meeting, the Working Group has approximately eight weeks to digest industry feedback, reconcile potentially conflicting positions on scalar calibration and interest rate sensitivity, vote on an updated draft, and prepare the document for (G) Committee adoption. The technical drafting group formed in June 2025 has been working on this for nearly a year, but the public engagement phase is compressed.

The IAIS Implementation Assessment Overlay

Running in parallel with the NAIC's domestic work is the IAIS's own implementation assessment program. The 2026 baseline self-assessment, now underway across 18 jurisdictions and approximately 60 IAIGs, will evaluate how each jurisdiction is implementing the ICS (or, in the US case, the comparable AM). Intensive targeted jurisdictional assessments begin in 2027 upon agreement from each jurisdiction.

For the NAIC, this creates an external accountability mechanism. The AM implementation must demonstrate not only domestic regulatory coherence but also international comparability with the ICS. The two convergence areas flagged by the IAIS (interest rate sensitivity and supervisory intervention timing) are the specific tests the US must satisfy. Failure to address them convincingly could reopen questions about AM comparability that were ostensibly settled in November 2024.

This connects directly to the broader global regulatory context. As we analyzed in our coverage of the IAIS 2026 baseline self-assessment, the assessment methodology will evaluate whether AM and ICS reference capital diverge on critical dimensions including private credit look-through, affiliated reinsurance consolidation, and illiquidity premium assumptions. The AM implementation review now under comment is the NAIC's opportunity to demonstrate it is addressing these divergences proactively.

Intersection With Concurrent NAIC Capital Reforms

The AM implementation does not operate in a vacuum. Several concurrent NAIC capital initiatives intersect directly with the group solvency review:

RBC governance framework. The RBC Model Governance Task Force's nine principles and process flowchart, adopted at the Fall 2025 meeting and refined at Spring 2026, govern how entity-level RBC factors evolve. Since the AM aggregates entity-level RBC results via ERR scalars, changes to the underlying RBC factors flow directly through to group-level AM outputs. The governance framework's "Equal Capital for Equal Risk" principle has direct implications for cross-formula calibration consistency, which in turn affects how accurately the AM captures group-level risk.

CLO capital overhaul. The Academy of Actuaries' proposed C-1 factors for CLOs would substantially increase capital charges for below-investment-grade tranches, with a December 31, 2026 target effective date. For PE-backed life insurers with concentrated CLO allocations, the entity-level RBC impact translates to group-level AM impact through the aggregation process. The AM's ability to capture this kind of concentrated asset risk at the group level, rather than just the entity level, is precisely what the IAIS comparability assessment is designed to test.

Negative IMR framework. The SSAP 109 revisions and negative IMR framework affect how interest-rate-driven capital impacts are recognized in statutory accounting. This intersects directly with the AM's interest rate sensitivity challenge: if US statutory accounting dampens the capital impact of rate movements at the entity level, the AM will similarly dampen it at the group level, potentially creating the comparability gap the IAIS flagged.

Investment subsidiary elimination. The Capital Adequacy Task Force's proposal to eliminate the investment subsidiary RBC category affects how certain group-level investment structures are captured in entity-level RBC. The AM aggregation process must account for how this category change redistributes capital requirements across entity types within a group.

What Actuaries at Affected Groups Need to Prepare

The compressed timeline between comment period close and expected Summer 2026 adoption means preparation work should be underway now, not after adoption is final.

Comment letter preparation. The May 11 deadline is two days away. Groups with specific concerns about scalar calibration, interest rate sensitivity disclosures, supervisory intervention triggers, or reporting requirements should submit comments to Ned Tyrrell (ntyrrell@naic.org) at the NAIC. Industry organizations (ACLI, NAMIC, PCI) will likely submit coordinated comment letters, but individual group perspectives on operational feasibility are valuable, particularly from groups with complex international structures where the ERR scalar methodology produces unexpected results.

GCC filing infrastructure. Groups already filing the GCC should begin mapping the enhanced reporting requirements described in the review against their current data collection and reporting processes. Interest rate sensitivity disclosures and reserve composition disaggregation will require data flows that may not exist in current GCC filing systems. The gap between current GCC template requirements and proposed AM-enhanced requirements represents the implementation work that needs to be scoped before the Summer meeting.

Internal capital model reconciliation. For groups running internal economic capital models alongside regulatory capital calculations, the AM implementation creates a new reference point. The GCC group capital ratio, the entity-level RBC ratios, and any internal economic capital metrics need to tell a consistent story. Where they diverge, groups should understand whether the divergence reflects genuine risk measurement differences or data/methodology artifacts that could draw supervisory scrutiny.

ORSA integration. The review's recommendation to clarify the ORSA guidance manual to designate the GCC as the regulatory capital measure at the IAIG head level means ORSA filings will need to explicitly address group capital adequacy using GCC outputs. Groups that currently treat their ORSA as primarily an entity-level exercise will need to build group-level capital assessment into their ORSA framework, connecting entity-level risk profiles to group-level capital implications.

Cross-border coordination. For groups with significant non-US insurance operations, the ERR scalar methodology determines how foreign subsidiary capital contributes to the group ratio. Actuaries should verify that the scalar adjustments applied to their non-US operations produce reasonable results under the ERR approach and prepare to explain any anomalies to group-wide supervisors. This is particularly important for groups with operations in jurisdictions where the local solvency regime differs substantially from US RBC in its balance between reserve conservatism and capital requirements.

Why This Matters for Group Capital Planning

The AM implementation review is not just a regulatory compliance exercise. It establishes the framework through which US group capital adequacy will be measured and compared internationally for the foreseeable future. The choices made in these four review areas, scalar calibration, interest rate sensitivity disclosure, supervisory intervention mechanics, and reporting requirements, will determine whether the US system is viewed as genuinely comparable to the ICS or as a politically negotiated exception that papers over fundamental measurement differences.

From tracking the GCC filing process since its May 2023 launch, patterns have emerged in how groups approach group-level capital assessment. Some treat the GCC as a compliance filing with minimal analytical engagement; others use it as a genuine risk management tool that informs capital allocation decisions. The AM implementation will push more groups toward the latter approach by connecting GCC outputs to international comparability standards and enhanced supervisory scrutiny.

The interest rate sensitivity area deserves particular attention from life actuaries. The gap between US statutory reserve responsiveness and ICS market-adjusted valuation is not a theoretical concern. In the 2022-2023 rate hiking cycle, the divergence between market valuations and statutory valuations of long-duration life liabilities was substantial. The AM's ability to capture and disclose this divergence, without requiring fundamental changes to US statutory accounting, is the central technical challenge of the implementation.

The pension risk transfer market provides an illustrative example. As PRT volumes continue to grow and life insurers absorb defined benefit pension liabilities, the interest rate sensitivity of these blocks varies significantly based on when the transfer occurred and what statutory valuation basis applies. As we covered in our analysis of pension risk transfer buy-in growth in 2026, the expanding PRT market creates exactly the kind of interest rate sensitivity concentration that the AM's enhanced disclosures are designed to capture at the group level.

For actuaries at groups near the IAIG threshold, the AM implementation timeline creates a planning imperative. Groups that do not currently qualify as IAIGs but are approaching the $50 billion asset or $10 billion premium thresholds should be monitoring the AM requirements proactively. The enhanced GCC reporting and ORSA integration requirements will apply immediately upon IAIG designation, and groups that wait until designation to begin implementation work will face a compressed and costly catch-up.

The Broader Regulatory Architecture

The AM implementation sits within a broader transformation of NAIC capital regulation that has accelerated since 2024. The RBC governance framework establishes how entity-level factors evolve. The CLO, collateral loan, and investment subsidiary proposals recalibrate specific asset risk charges. The C-3 field test modernizes interest rate risk charges using updated economic scenario generators. And the AM implementation determines how all of these entity-level outputs aggregate to group-level capital adequacy for internationally active groups.

These workstreams are not independent. Changes to entity-level RBC factors flow through the AM's aggregation process to affect group-level ratios. Enhanced AM reporting requirements create new data demands that intersect with existing GCC filing processes. ORSA integration connects quantitative capital measures to qualitative risk assessment. The challenge for actuaries at affected groups is understanding the full system of interactions, not just the individual components.

The NAIC has structured its working groups to handle these interactions: the AMI Working Group under the International Insurance Relations (G) Committee, the GCC (E) Working Group under the Financial Condition (E) Committee, the RBC Model Governance Task Force under the Executive (EX) Committee. But the cross-committee coordination required to ensure consistency across all of these concurrent initiatives is itself a governance challenge. The post-adoption referral of AM recommendations to the Financial Condition (E) Committee will test whether the NAIC's committee structure can manage this level of concurrent, interconnected regulatory development.

Further Reading

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