The DRG segment assigns a Diagnosis-Related Group to a visit for inpatient case-mix classification and reimbursement. It carries the DRG code, when it was assigned and approved, outlier information, and the payor, supporting prospective-payment billing.
Purpose
DRG conveys the case-mix classification of an inpatient stay: the group code (DRG-1), assignment and approval status, outlier type/days/cost, and the responsible payor — the inputs to DRG-based reimbursement.
Used in
DRG appears in ADT (with the visit) and in billing/financial messages (BAR, DFT). See ADT.
Field-by-field reference
Source: HAPI HL7v2 v2.5.1 javadocs (DRG) for sequence, name, and data type. Length is not published in the javadocs (—); Required and Table # are filled from the HL7 v2.5.1 standard where well-established.
| Seq | Name | Data Type | Length | Req | Repeat | Table # | Description |
|---|---|---|---|---|---|---|---|
| DRG-1 | Diagnostic Related Group | CE | — | O | — | HL70055 | The assigned DRG code. |
| DRG-2 | DRG Assigned Date/Time | TS | — | O | — | — | When the DRG was assigned. |
| DRG-3 | DRG Approval Indicator | ID | — | O | — | HL70136 | Approved (Y/N). |
| DRG-4 | DRG Grouper Review Code | IS | — | O | — | HL70056 | Grouper review code. |
| DRG-5 | Outlier Type | CE | — | O | — | HL70083 | Type of outlier. |
| DRG-6 | Outlier Days | NM | — | O | — | — | Outlier day count. |
| DRG-7 | Outlier Cost | CP | — | O | — | — | Outlier cost. |
| DRG-8 | DRG Payor | IS | — | O | — | HL70229 | Responsible payor. |
| DRG-9 | Outlier Reimbursement | CP | — | O | — | — | Outlier reimbursement. |
| DRG-10 | Confidential Indicator | ID | — | O | — | HL70136 | Confidential (Y/N). |
| DRG-11 | DRG Transfer Type | IS | — | O | — | HL70415 | Transfer type. |
Most-used fields
- DRG-1 Diagnostic Related Group is the assigned group code that drives reimbursement.
- DRG-5 to DRG-9 capture outlier handling when a stay exceeds normal parameters.
Version differences (2.3 to 2.8.2)
- 2.4/2.5: outlier and transfer fields (DRG-5 onward, DRG-11) added.
- DRG-1 coding aligns to the applicable grouper version per payor.
Common mistakes
- Sending DRG without the grouper context (DRG-4) needed to interpret the code.
- Ignoring DRG-5/DRG-6 outlier data that affects payment.
Examples
Minimal valid DRG:
DRG|470^Major Joint Replacement^HL70055
Fully-populated DRG:
DRG|470^Major Joint Replacement^HL70055|20260612080000|Y|0^No Review^HL70056|||||N
Annotated breakdown of the fully-populated example (selected fields):
DRG ← segment ID
470^Major Joint Replacement^HL70055 ← DRG-1 Diagnostic Related Group
20260612080000 ← DRG-2 Assigned Date/Time
Y ← DRG-3 Approval Indicator
0^No Review^HL70056 ← DRG-4 Grouper Review Code
N ← DRG-10 Confidential Indicator
In-context inside an ADT^A01 (admit with DRG):
MSH|^~&|REG|MERCYGEN|EHR|MERCYGEN|20260612080000||ADT^A01^ADT_A01|MSG907|P|2.5.1
PID|1||MR12345^^^MERCYGEN^MR||DOE^JOHN^Q||19800101|M
PV1|1|I|3WEST^301^A
DG1|1||M17.0^Bilateral primary osteoarthritis of knee^I10
DRG|470^Major Joint Replacement^HL70055|20260612080000|Y
In-context inside a BAR^P01 (billing account):
MSH|^~&|ADT|MERCYGEN|FIN|MERCYGEN|20260612090000||BAR^P01^BAR_P01|MSG908|P|2.5.1
PID|1||MR12345^^^MERCYGEN^MR||DOE^JOHN^Q||19800101|M
DRG|470^Major Joint Replacement^HL70055|20260612080000|Y
FHIR mapping
No segment-level ConceptMap is published in the v2-to-FHIR IG for DRG. The DRG concept maps conceptually to billing resources (Claim/ClaimResponse) or an Encounter/Condition coding; implementations define this locally.
Engine considerations
- DRG-1 coding depends on the grouper/version — preserve the full CE so the grouper is identifiable.
- Normalize Y/N indicators (DRG-3/DRG-10) per table 0136.
How Vorro parses and produces DRG
Vorro preserves the full DRG coding triplet and outlier fields, normalizes indicator flags, and surfaces the DRG for case-mix and reimbursement workflows.
Related pages
- DG1 — the diagnoses that drive DRG assignment.
- PR1 — procedures contributing to the DRG.
- ADT messages — where DRG accompanies the visit.
