Initiatives intended to reduce the frequency and impact of medical errors generally rely on recognition and disclosure of medical errors. However, fear of malpractice liability is a barrier to physician disclosure. Some U.S. state legislatures have attempted to encourage physicians to disclose medical errors by enacting "apology laws." The authors reviewed the codified statutes of each of the 50 states and the District of Columbia to determine the prevalence and characteristics of such apology laws. They found that many states have recently adopted apology laws and that there is variability in these laws. The authors review some of the important differences in these laws and explore the potential impact of apology laws.