Retrospective reports of personal events constitute the principal data source for much applied social science research. Such reports are known to be subject to biases and errors of inference. In health surveys, for example, events associated with chronic conditions are particularly likely to be under-reported (Jabine, 1987). In this series of studies we apply perspectives and tools from psychological studies of memory to the problem of understanding and improving reports of past untilization of health care. In two studies we found that subjects report using different strategies to answer questions about how often they have seen a doctor over the past 12 months, depending on the type of doctor's visit and its frequency. A third study, in which subjects' recall was checked against medical records, provided evidence that individual health events within a group of recurring, similar events are much less likely than non-recurring events to be recalled. In Experiment 4 we tested the efficacy of cognitively oriented intervention techniques designed to (1) help subjects decompose their molar memories of groups of similar events into individual events and (2) place all remembered health events into a personal timeline. The intervention more than doubled the proportion of recurring events on the medical record that was recalled. In addition, the proportion of events that could be dated, and the accuracy of dates provided, both rose.