Model Risk Directory emblemModel Risk Directory
Model LifecycleProxy model

Surrogate model

A simpler model used to approximate, explain, benchmark, or replace aspects of another model. Governance should document its purpose, fidelity, limitations, validation, and the decisions that rely on it.

Last updated: Last reviewed by: Model Risk Directory editorial team

How the term is used in model risk management

A simpler model used to approximate, explain, benchmark, or replace aspects of another model. Governance should document its purpose, fidelity, limitations, validation, and the decisions that rely on it. The exact implementation varies by institution, model type, risk rating, and governing framework. Use the linked regulatory pages and buyer guides below for scope-specific requirements.

Related glossary terms

Benchmarking (model risk)ExplainabilityChampion-challenger

Guides and frameworks that use this term

GuideModel Risk ValidationModel risk validation is the independent testing of a specific model's conceptual soundness, ongoing performance, and outcomes, performed by staff or a third-party firm genuinely separate from that model's development. It is the 'effective challenge' function required under SR 26-2 and SR 11-7, distinct from broader model risk management program design.FrameworkMAS AI MRMThe MAS AI MRM paper reports good practices observed in a thematic review of selected banks. It covers AI governance, inventories, materiality assessment, data, development, independent validation, deployment, monitoring, change, generative-AI risks, and third-party models. It is supervisory guidance and observed practice, not a general statutory MRM rule.