State and local health departments have become increasingly involved in investigations of transfusion-transmitted infections and other transfusion-related adverse events and provide regulatory oversight of hospital transfusion services. Since 2010, the Hemovigilance Module of the National Healthcare Safety Network (NHSN) has been available for voluntary reporting of transfusion-related adverse events in the United States. Adverse event reporting includes incidents (i.e., errors, “near misses”), adverse reactions (e.g., transfusion-transmitted infection), and denominators (monthly summary of components transfused or discarded and patient samples collected). In 2013, the Massachusetts Department of Public Health (MA-DPH) mandated that all licensed blood banks and blood services in the state utilize the NHSN Hemovigilance Module for all monthly transfusion activity and adverse event reporting. Since virtually every hospital in the U.S. now uses NHSN for reporting healthcare-associated infections to federal and state agencies, familiarity with NHSN participation is high. The NHSN Hemovigilance Module offers a secure, internet-based method for collecting incidents, adverse reactions, and denominators but also allows facilities to share their data, electronically, with other organizations (e.g., state and local health departments) using the Group function. We propose this roundtable session to highlight the functionality of the NHSN Hemovigilance Module and the Group function for states considering use to facilitate mandatory reporting of transfusion safety data. We will also discuss the advantages that the Module provides for conducting hemovigilance and providing state and local public health agencies with surveillance and epidemiological tools to facilitate regulatory oversight. Specific strategies from MA-DPH experience with launching mandatory statewide reporting will be presented, including the process for stakeholder input, facility outreach, and statewide education to facilitate accurate, timely, and consistent reporting by all transfusion facilities.