This Tool for Measuring Adverse Events provides an easy-to-use method for accurately identifying adverse events (harm) and measuring the rate of adverse event incidence over time in skilled nursing facilities (SNFs). It is a useful way to tell if changes being made are improving the safety of care processes. This tool provides step-by-step instructions for using this methodology, detailed guidance on designing a Trigger Tool review, a list of SNF-specific triggers and definitions, examples of adverse events that occur in SNFs, and an extensive Frequently Asked Questions section.