When to Adopt Model Updates

As AI development increasingly involves models adapted to downstream settings, a new algorithmic challenge for developers has surfaced: deciding when to adopt model updates. Currently, the only reliable approach is to retrain on new upstream models and then evaluate extensively, which can be prohibitively expensive. We introduce a framework for assessing when to propagate newly released model versions to downstream applications that does not require access to upstream data or retraining a priori. Our framework incorporates geometric similarity and information-theoretic sufficiency to determine when an upstream update substantially shifts the representational basis recruited for a downstream task. This enables targeted update adoption, and supports emerging norms for coordinating AI supply chain infrastructure.