Surveys that rate how persons enrolled in HMOs and other types of health coverage feel about their health care are used to bolster claims that HMOs provide inferior quality care, providing justification for patient protection legislation. This research illustrates that the conventional wisdom regarding inferior care in HMOs may color how people assess their health care in surveys, resulting in survey findings biased toward showing HMOs provide inferior care and reinforcing existing stereotypes. Using merged data from the Community Tracking Study Household and Insurance Followback surveys, we identify privately insured persons who correctly and incorrectly know what kind of health plan they are covered by. Nearly a quarter misidentified their type of health coverage. Differences between responses by HMO and non-HMO enrollees to questions covering satisfaction with health care and physician choice, the quality of the last physician's visit, and patient trust in their physician shrink or disappear when we control for beliefs about what type of plan they are covered by. Results suggest that researchers and policy makers should be cautious about using consumer surveys to assess the relative quality of care provided under different types of health insurance.