The annual cost of preventable adverse events to the United States health care system has been estimated as $17 billion, but this study estimates the total social cost of adverse events to approach $950 billion, or more than 40% of total health care spending. In this context, the social cost refers to the economic costs associated with lives lost or injuries suffered as a consequence of adverse events, be they preventable or non-preventable. The authors advocate for a no-fault malpractice system as a potential means of improving the equity of compensation for patients who suffer adverse events, given the documented ineffectiveness of the current malpractice system at compensating patients who suffer preventable harm. A no-fault system is currently in place in New Zealand.