Compliance Guide

    SR 26-2 Model Validation: Frequency and Independence Expectations for AI

    Read SR 26-2 against SR 11-7, the prior supervisory baseline, on two questions: how often models are validated and how independent the validators are. Whatever cadence a program sets, periodic validation is a point-in-time assessment. For AI systems that behave dynamically in production, it does not show what the system was allowed to do, or did, between cycles. That evidence has to be produced continuously. Runtime policy enforcement can supply it as a complement to independent validation, not a substitute.

    Evidence to retain between validation cycles

    • The policy in force for each AI use case, with the dates it changed and who approved the change.
    • A record of each policy decision on an interaction or tool call: allowed, redacted, blocked, rate limited or escalated.
    • Human approval records for escalated actions, including who approved and when.
    • Monitoring results for output quality and unexpected behavior, with thresholds and the actions taken when they were crossed.
    • Revalidation triggers raised during the interval and how each was resolved.
    • Retention and data residency settings, so the evidence remains available for the period the firm has set.

    Independent validation and runtime enforcement are different controls

    Timing

    Validation is periodic and event-driven. Runtime enforcement operates on every interaction as it occurs.

    Question answered

    Validation asks whether the model is conceptually sound, well implemented and fit for its use. Enforcement records what the system was allowed to do and did.

    Who performs it

    Validation requires people independent of development. Enforcement applies policy defined by the firm and runs automatically.

    Scope

    Validation covers theory, data, testing, performance, documentation and implementation controls. Enforcement covers individual interactions and tool calls.

    Output

    Validation produces findings and recommendations. Enforcement produces a continuous evidence record.

    What it cannot do

    Validation cannot observe the interval between cycles. Enforcement cannot challenge a model's methodology or replace independent review.

    Reading SR 26-2 against SR 11-7 on validation frequency

    SR 11-7, Guidance on Model Risk Management, is the baseline most model risk programs were built on. A November 2025 Federal Register footnote confirms it applies to all supervised insurance organizations, so its principles reach beyond banks. A comparison with SR 26-2 should be made clause by clause, using the text of each. Two questions organize it: what sets the validation cadence, and what triggers validation outside that cadence.

    For frequency, separate three design choices that programs often blur. The first is the scheduled cycle, usually tied to model risk tiering. The second is event-driven revalidation, such as a material change to the model, its input data or its intended use. The third is ongoing monitoring, which runs continuously between cycles and feeds the other two. A change in guidance language can affect any one of these without affecting the others, so record your findings against each separately.

    Other regimes show how cadence can be layered. One clearing-agency regime requires daily backtesting of model performance, periodic sensitivity analyses and annual validation of models. A separate clearing-agency policy describes monthly reverse stress testing alongside annual independent validation. These are different regimes and not bank requirements. They illustrate that a single validation date is rarely the only assurance activity, and that fast monitoring cycles often sit beneath a slower validation cycle.

    Independence: what to compare

    Independence is easier to test than to describe. When comparing SR 26-2 with prior expectations, look at four things: organizational separation between validators and model developers or owners, the reporting line of the validation function, the competence and authority of validators, and the role of internal versus external reviewers.

    Each one affects design. Separation determines who may validate a model and who may not. Reporting lines determine whether findings reach senior risk governance without filtering by the business line that owns the model. Competence matters because a validator who cannot evaluate a model's methodology, data and implementation controls cannot meaningfully challenge it. Authority matters because findings need a defined path to resolution. Clearing-agency practice offers a simple example of the last point, with an independent validation team reporting findings to a risk committee.

    External reviewers can add capacity or specialist skill, but they do not remove the need for an internal owner of the validation outcome. Independence also has limits for AI. A validator can be fully independent and still have no visibility into what a production system did last Tuesday.

    The gap for AI systems that change behavior in production

    Validation, however frequent and independent, assesses a model at a moment in time. Dynamic AI systems create exposure between those moments. NIST's Center for AI Standards and Innovation states that post-deployment monitoring is crucial for validating that AI systems operate reliably in real-world scenarios. It points to unforeseen outputs caused by model non-determinism or dynamic input conditions, and to the need for visibility into unexpected consequences in deployment contexts.

    This supports a practical reading. Even if a validation cycle is on schedule, a program using AI needs to be able to answer questions about the interval since the last cycle. What was the system permitted to do? Which requests were blocked or redacted? Which actions went to a human for approval? What did it actually do? Where a model is reached through a third party or acts through tools, these questions apply to each interaction and each tool call, not only to the model.

    None of this makes validation less important. It means validation findings and runtime evidence answer different questions, and a program needs both.

    How runtime enforcement produces this evidence

    Trussed enforces policy in the execution path across models, agents, tools, MCP servers, AI sites and coding assistants. Policy is enforced at runtime, not reviewed after the fact. Each decision to allow, redact, block, rate limit or escalate for human approval is applied to an individual interaction or tool call, and that enforcement generates continuous, audit-ready evidence. The evidence is mapped to HIPAA, NAIC, NYDFS, the EU AI Act and NIST. Deployment is self-managed in the customer cloud, with configurable retention and data residency.

    The scope is deliberate. This evidence shows what the AI was allowed to do and what it did at the level of single interactions and tool calls. It does not replace independent validation, and it does not describe model lineage, model provenance or end-to-end tracing of agentic workflows.

    In production, Trussed has run continuously for more than 18 months in a regulated enterprise, with 99.95% uptime on live traffic, more than 100 models under one policy plane and more than 30 GB of audit evidence generated per day. Customers span four regulated verticals: insurance, pharma, healthcare and education.

    Two layers of assurance for AI in production

    Label: Independent validation

    Description: Periodic, point-in-time challenge of model design, data, performance and use by people separate from development.

    Label: Runtime enforcement

    Description: Policy applied to each AI interaction and tool call as it happens: allow, redact, block, or escalate for human approval.

    Label: Between-cycle evidence

    Description: Durable records of what the AI was permitted to do and what it did, retained for review.

    Plan the evidence your validation cycle cannot produce

    Walk through how enforcement in the execution path generates audit-ready evidence between validation cycles, and where independent validation still has to do the work.

    See How Evidence Is Produced