This presentation, delivered at the ISPOR 2026 Workshop, explores a paradigm shift in health economic modeling, using AI not as a standalone tool, but as a reasoning engine within a structured multi-agent platform. It demonstrates how researchers can collaborate with AI to develop robust models in both Excel and R. Crucially, this approach generates more than just executable code, producing a comprehensive paper trail. By combining deterministic scaffolding with AI-driven extraction and human-in-the-loop oversight, the platform automatically generates full documentation of user interactions, model assumptions, data sources, design choices, and rigorous validation and verification results. This is a collaborative model development platform built for the scientific rigor of HEOR.