As precision medicine gains momentum and in vitro diagnostics (IVDs) become increasingly used in clinical trials, pharmaceutical and biotechnology companies must quickly become familiar with the FDA’s investigational device framework. Based on concerns that drug clinical trial sponsors do not appreciate the need to follow device regulations when using “investigational” IVDs in clinical trials, in its draft guidance, FDA provides more structure around the incorporation of IVDs into clinical trials, and sets out its expectations about sponsors’ scope of review of the risk of use of such IVDs. The draft guidance will need to be factored into how pharmaceutical and biotechnology clinical trial sponsors use IVDs in clinical trials and work with device partners.