Patients may provide valuable insights into potential safety problems. This study describes the development and initial validation of a survey tool for capturing patient feedback about safety in the ambulatory setting. This tool expanded the previously developed patient measure of safety questionnaire to include four primary care–specific domains: continuity of care, external policy context, primary–secondary interface, and referrals. The survey was developed by an expert panel through a modified Delphi process and was well received by patients and staff during face validity testing. This tool aims to provide patient perspectives to primary care organizations to focus improvement efforts in these settings. A prior AHRQ WebM&M interview discussed the emerging field of ambulatory patient safety.