ADT Specification

Upon implementation of the ADT Service, hospitals shall provide in real-time (i.e., seconds, not minutes or hours), HL7 ADT messages for all payers to the ADT Service Vendor to the extent allowed by applicable law. ADT messages should be submitted according to the HL7 ADT Specification spreadsheet.

HL7 Event Types

HL7 event types for this service include admissions, discharges, and transfers from acute care and psychiatric hospitals for inpatient services and emergency department visits.

HL7 Segments

The HL7 specification includes required and expected (nice-to-have) data segments:

  • Required: Message Header (MSH), Event Type (EVN), Patient Identification (PID), Patient Visit (PV1), Merge Patient Information (MRG)
  • Expected: Patient Visit – Additional Information (PV2), Procedures (PR1), Insurance (IN1), Guarantor (GT1), Diagnosis (DG1), Next of Kin / Associated Parties (NK1), Notes and Comments (NTE)

Required Fields

The specification includes required and expected fields. Ai will work with hospitals on a best effort basis to receive all TennCare-required fields, understanding this can be limited by hospital IT systems and provider workflows around capturing specific data (or the timing thereof).

Code / Code Set Normalization

Ai will work with facilities on a best effort basis to receive required fields and normalize all reported fields to meet TennCare specifications.

Data Quality

Image of the HL7 ADT Specifications spreadsheet

The HL7 ADT Specification spreadsheet includes a Data Quality tab which will be maintained for the ADT Service. It is expected that all hospitals will provide high quality, consistent and complete data. For example, at minimum, it should be possible to determine inpatient and emergency department admissions and discharges from the ADT messages. Further, other key fields such as a free-text admission reason and a codified discharge diagnosis are also expected from all sources (understanding that the codified discharge diagnosis may lag the actual discharge event by a few days).


The THA Health Information Network (THA HIN) was formed in 1999 by the Tennessee Hospital Association to assist member hospitals in meeting the state mandated hospital discharge data reporting requirements.


THA Health Information Network
5201 Virginia Way
Brentwood, TN 37027

Toll Free: 1-866-2THA-HIN