The capacity of electronic health records (EHRs) to capture desired information depends on the practices of health care providers. These practices have not been well studied in relation to post-traumatic stress disorder (PTSD). This qualitative study investigated how providers write EHR notes on PTSD through 38 interviews with providers working at five Veterans Affairs (VA) hospitals across the United States of America. Two overarching themes were prominent in the results. Providers used progress notes primarily to remember and access details for direct patient care, but only rarely for care coordination. Providers infrequently recorded information not judged to directly contribute to improved care, sometimes deliberately omitting information perceived to jeopardize patients' access to, or quality of, care. Omitted information frequently included sexual or non-military trauma. Understanding providers' thought processes can help clinicians be aware of the limitations of EHR notes as a tool for learning the histories of new patients. Similarly, researchers relying on EHR data for PTSD research should be aware of likely areas of missing data.