Nature Biomedical Engineering, Published online: 14 August 2026; doi:10.1038/s41551-026-01778-5 The potential for machine learning to reshape the medical landscape is vast, and we are in the midst of an explosion in tool development. In this Focus issue, we share both critical and forward-looking insights from experts on artificial intelligence in medicine and emphasize how thoughtful engineering is poised to make the types of tools needed for long-term clinical impact.