This transaction set communicates health care services review information, typically sent by a health plan, utilization review organization, or third-party administrator in response to a prior authorization request or during the review of proposed services. The sender informs the recipient—usually a provider, facility, or practitioner—about the status, findings, or conditions related to a services review. Key segments include the HL (Hierarchical Level) segment, which organizes the transaction’s hierarchical structure; the UM (Health Care Services Review Information) segment, which conveys the core review determination; and the NM1 (Individual or Organizational Name) segment, which identifies parties involved such as the provider, patient, or reviewing entity.

For a concrete example, Blue Cross Blue Shield sends a 278 transaction to Community Medical Center to communicate the results of a pre-authorization review for a patient’s proposed spinal fusion surgery. The message includes the HL segment establishing the hierarchical levels for the request, the UM segment indicating that the service is approved for an inpatient stay, and relevant certification segments such as CR1 or CR2 if specialized conditions apply. The NM1 loops identify the surgeon, the facility, and the patient. Additionally, DTP segments specify the approved service dates, HI segments document the diagnosis and procedure codes under review, and MSG segments may include any reviewer comments or conditions for approval.