The EU AI Act imposes stringent obligations on high-risk AI systems concerning transparency, reproducibility, traceability, safety, robustness, fairness, accountability, cybersecurity, and human oversight. Contemporary AI systems-dominated by large stochastic models-lack structural mechanisms to guarantee reproducible and deterministic operation. Their nondeterministic outputs, drifting internal representations, and sampling-based inference methods create compliance and auditability challenges. This paper presents Deterministic AI, grounded in the Deterministic Computation Law (DCL): R = H(D(P)) as a computational framework that inherently aligns with the EU AI Act. Deterministic AI’s canonicalization of computation, reproducible internal states, stable evaluation mechanisms, and deterministic logs enable a compliance-first architecture. The paper demonstrates how deterministic models enable predictable behavior, interpretable reasoning, formal analysis, audit-ready traceability, deterministic safety evaluation, and drift-free lifecycle governance. Modern stochastic AI remains empirical in foundation and nondeterministic in operation, relying on probabilistic training and inference mechanisms that undermine strict reproducibility. Deterministic AI, by contrast, offers a mathematically principled, reproducible substrate that supports the level of governance envisioned by European regulators. We argue that deterministic computation is the most direct and robust architecture for achieving high-risk AI compliance under the EU AI Act.