The authors analyzed the relationship between negligent medical error and the filing of medical liability claims in a review of 15,000 hospital discharges in Utah and Colorado in 1992, a sample distinct in time and population from similar studies performed in California and New York. They reviewed each case for the presence of iatrogenic injury resulting from negligence and matched the set of cases against the medical malpractice claims filed in the two states. The authors find 97% of adverse events caused by negligence did not result in malpractice claims. Of the 18 malpractice claims in the sample, 14 were made in the absence of any negligence. Thus, the authors found almost no relationship between actual negligence and the filing of malpractice claims. The authors explore the relationships among poverty, advanced age, and a decreased likelihood of filing a claim and review options for comprehensive malpractice reforms.