Information blocking poses threats to patient safety and to the efficacy and effectiveness of our health care system, by inappropriately impeding the flow or use of information. Enacted in 2016, the 21^st Century Cures Act prohibited health care providers, health information technology (IT) developers of certified health IT, and health information exchanges or networks from engaging in information blocking.  The Office of the National Coordinator for Health Information Technology (ONC) issued a final rule in 2020 setting out certain exceptions to the definition of information blocking.  More recently, in June 2023, the Department of Health and Human Services Office of Inspector General (OIG) promulgated a final rule setting out the investigations and enforcement process against health IT developers of certified health IT and health information exchanges and networks. OIG’s Final Rule became effective, and enforcement began, on September 1, 2023.