Preliminary Reporting Tiers for AI Bio Safety Evaluations Frontier AI models and systems are particularly promising for advancing medicine and public health. At the same time, their knowledge of biology and ability to reason about biological concepts may also be misused in ways that pose significant risks to public safety and security. To manage those risks, many frontier AI developers have published safety frameworks in which they commit to evaluating their systems for biological knowledge and capabilities that could pose large-scale risks to public health and safety.