NEW 2026 Hospital Discharge Data System (HDDS) Manual
The Tennessee Department of Health (TDH), in collaboration with the Tennessee Hospital Association Health Information Network (THA HIN), has released the 2026 Hospital Discharge Data System (HDDS) User Manual. The TDH sent you two memos regarding the changes:
You can access the complete 2026 manual by clicking here.
You will find a summary of changes to this manual on pages 6-7. We encourage you to review all changes.
However, there are two notable changes for THA members who report their data directly to THA HIN via HIDInet. They are as follows:
- Excessive use of unknowns in provider/physician fields
| Field No. | Description | Positions | HDDS Manual Data Dictionary Page No. |
| 242-244 | Attending Provider Name and Identifiers | 1946-1970 | 107 |
| 245-247 | Operating Physician Name and Identifiers | 1971-1995 | 109 |
| 248-250 | Other Provider (Individual) Name and Identifiers 1 | 1996-2020 | 111 |
| 251-253 | Other Provider (Individual) Name and Identifiers 2 | 2021-2045 | 113 |
The first component of this field has two parts and uses twelve positions, (1) the profession code and (2) the TN state license number.
- The first part is two positions and contains the provider’s profession code
- The second part is the next ten positions following the profession code and contains the TN state license number for the provider, using leading zeros to fill all ten spaces.
Beginning with the submission of the Q4-2026 data, due by March 1, 2027, the use of the unknown code, UK9999999999, for all provider fields listed in the table above, will be limited to less than 40% in the inpatient and outpatient datasets.
- Over the coming weeks you will be able to see how often you are using the unknown code, UK9999999999, in your hospital’s/hospital system discharge data for all four of the fields listed in the table above, separating inpatient and outpatient calculations. This will be posted to page 1 of your verification report(s), and the report(s) will be available to view in HIDInet after you submit your Q2-2026 data, as usual. This will allow you to see if you need to make improvements to your data prior to the effective date of this new rule.
- Once this new rule is implemented with the submission of your Q4-2026 data, if the usage is above the 40% allowable threshold in any of the four provider fields listed above, in either your inpatient or outpatient data files, your data will not be accepted by the TDH and you will be required to make corrections to the applicable fields to bring them below 40%.
Please note: The ability to make online corrections will be implemented for the Q4-2026 data submission period to all four of these fields in HIDInet (if you use the unknown code, UK9999999999, and are above the 40% allowable threshold). However, as always, we encourage you to make the changes/corrections internally to your data file and resubmit the full data file.
- Freestanding Emergency Department (FSED) Identifier
| Field No. | Description | Positions | HDDS Manual Data Dictionary Page No. |
| 254b | Freestanding Emergency Department Identifier | 2051-2057 | 116 |
This is a new field to properly identify an off-campus FSED, if applicable to your hospital(s). If the reporting/parent hospital does not have an off-campus FSED, this field is left blank.
This field does not have the standard 180-day effective rule. Over the coming days, we will reach out to each hospital/system that has an off-campus FSED. We will provide you with the reporting format information as well as your FSED identification number that has been assigned. We encourage you to read through page 116 of the new 2026 HDDS manual prior to our outreach.
We will encourage each parent hospital that is reporting for an off-campus FSED to begin the new reporting process with the Q3-2026 data submission which is due by November 29, 2026.
Special Note: This new field is shared with field 254a which is your hospital’s JAR ID. There have been no changes to the way you report your JAR ID – the field length was shortened to accompany the new FSED identifier field. The JAR ID field is now 5 characters in length (previously 12 characters). Please review page 115 of the HDDS manual to see the full information on this field.