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MS-DRG 018 · MDC PRE · Medical

MS-DRG 018: Chimeric Antigen Receptor (CAR) T-Cell and Other Immunotherapies

Reviewed by QuickIntell RCM Editorial Team · Last reviewed

Data effective
Data currency: IPPS Table 5 FY2027 final rule (effective October 1, 2026); Definitions Manual v44 (effective October 1, 2026). Next CMS release: April 1, 2027 (v44.1 mid-year update), then the FY2028 final rule in August 2027.

Key facts for DRG 018

FY2027 relative weight
45.1270
Higher than 100% of all MS-DRGs
Change vs FY2026
+4.5%
FY2026 weight 43.1830
Geometric mean LOS
11.4 days
Arithmetic mean 13.3 days
MDC
PRE
Pre-MDC (transplants, tracheostomy, ECMO)
Severity level
single severity level
Transfer policy
Not a transfer DRG

TL;DR

MS-DRG 018 is a medical group in MDC PRE (Pre-MDC (transplants, tracheostomy, ECMO)) at a single-severity group of its family. CMS assigns it a FY2027 relative weight of 45.1270 with a geometric mean length of stay of 11.4 days and an arithmetic mean of 13.3. Its weight moved up 4.5% from FY2026 (43.1830). That weight is higher than 100% of all medical and surgical MS-DRGs. CMS does not split this group by severity. The v44 Definitions Manual assigns it through 8 operating room procedures codes.

What changed from FY2026 to FY2027

CMS recalibrates every MS-DRG weight annually from the prior year's MedPAR claims. For DRG 018 the FY2027 relative weight is 45.1270 against 43.1830 in FY2026, a rise of 4.50%, which exceeds the 2% threshold worth re-checking in contract models.

FY2026 versus FY2027 payment factors for MS-DRG 018
MetricFY2026FY2027Change
Relative weight43.183045.1270+1.9440
Geometric mean LOS (days)12.411.4-1.0
Arithmetic mean LOS (days)14.713.3-1.4
Weights shown are the FY2027 final values after the 10% cap on year-over-year reductions where applicable.

CC and MCC family

DRG 018 stands alone: CMS does not split this base group by CC or MCC severity, so complication documentation does not move the assignment, although it still affects quality and risk-adjustment reporting.

Grouper logic (v44 Definitions Manual)

Operating Room Procedures: 8 ICD-10 codes drive assignment to this group.

Operating Room Procedures codes assigned to DRG 018 (sample)
ICD-10 codeDescription
XHR0XGAReplacement of Head and Neck Skin with Prademagene Zamikeracel, Genetically Engineered Autologous Cell Therapy, External Approach, New Technology Group 10
XHR1XGAReplacement of Chest Skin with Prademagene Zamikeracel, Genetically Engineered Autologous Cell Therapy, External Approach, New Technology Group 10
XHR2XGAReplacement of Abdomen Skin with Prademagene Zamikeracel, Genetically Engineered Autologous Cell Therapy, External Approach, New Technology Group 10
XHR3XGAReplacement of Back Skin with Prademagene Zamikeracel, Genetically Engineered Autologous Cell Therapy, External Approach, New Technology Group 10
XHR4XGAReplacement of Right Upper Extremity Skin with Prademagene Zamikeracel, Genetically Engineered Autologous Cell Therapy, External Approach, New Technology Group 10
XHR5XGAReplacement of Left Upper Extremity Skin with Prademagene Zamikeracel, Genetically Engineered Autologous Cell Therapy, External Approach, New Technology Group 10
XHR6XGAReplacement of Right Lower Extremity Skin with Prademagene Zamikeracel, Genetically Engineered Autologous Cell Therapy, External Approach, New Technology Group 10
XHR7XGAReplacement of Left Lower Extremity Skin with Prademagene Zamikeracel, Genetically Engineered Autologous Cell Therapy, External Approach, New Technology Group 10

Documentation and denial exposure

As a medical DRG, assignment depends on the principal diagnosis sequenced from the attending's documentation; a secondary condition sequenced first, or a symptom code in place of the confirmed diagnosis, changes the MDC or the DRG. Because this family has no severity split, review risk concentrates on medical-necessity of the admission itself and on the two-midnight benchmark. Typical inpatient denial codes for this group: CARC 16 (claim lacks information needed to group the stay), CARC 50 (the admission or procedure is judged not medically necessary), CARC 97 (a service is bundled into the DRG payment).

How QuickIntell uses DRG 018 data

QuickCode groups inpatient encounters against the current v44 logic, flags CC and MCC candidates that lack supporting documentation, and shows the weight difference across the family before the claim drops. QuickScribe captures the attending's language that supports severity, and QuickRCM works DRG-validation denials with the grouper evidence attached.

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Frequently asked questions — DRG 018

What is MS-DRG 018?

MS-DRG 018 is "Chimeric Antigen Receptor (CAR) T-Cell and Other Immunotherapies", a medical Medicare Severity Diagnosis-Related Group in MDC PRE, Pre-MDC (transplants, tracheostomy, ECMO). Medicare pays inpatient stays grouped here at the hospital's base rate multiplied by the DRG relative weight.

What is the FY2027 relative weight for DRG 018?

The FY2027 relative weight is 45.1270 (IPPS final rule Table 5, effective October 1, 2026). In FY2026 it was 43.1830, a change of +4.5%.

What is the average length of stay for DRG 018?

CMS reports a geometric mean length of stay of 11.4 days and an arithmetic mean of 13.3 days for FY2027. The geometric mean is used for transfer-payment calculations.

What documentation supports the severity level of DRG 018?

DRG 018 has no CC or MCC sibling, so secondary-diagnosis capture does not change the group or its weight. Review effort belongs instead on the principal diagnosis sequencing and the procedure codes that place the stay in this group, and on medical necessity of the inpatient admission itself under the two-midnight benchmark, which is where denials for single-severity groups concentrate.

Which codes group to DRG 018?

The v44 Definitions Manual lists 8 operating room procedures codes for this group. Examples from the operating room procedures list: XHR0XGA (Replacement of Head and Neck Skin with Prademagene Zamikeracel, Genetically Engineered Autologous Cell Therapy, External Approach, New Technology Group 10); XHR1XGA (Replacement of Chest Skin with Prademagene Zamikeracel, Genetically Engineered Autologous Cell Therapy, External Approach, New Technology Group 10); XHR2XGA (Replacement of Abdomen Skin with Prademagene Zamikeracel, Genetically Engineered Autologous Cell Therapy, External Approach, New Technology Group 10); XHR3XGA (Replacement of Back Skin with Prademagene Zamikeracel, Genetically Engineered Autologous Cell Therapy, External Approach, New Technology Group 10).

Is DRG 018 a post-acute transfer DRG?

No. DRG 018 is not on the FY2027 post-acute care transfer list, so the transfer per-diem policy does not apply to it.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-01. Verify against the primary file before billing or contracting decisions.

Disclaimer

This page is an operational reference compiled from the CMS IPPS FY2027 final rule (Table 5) and the v44 ICD-10 MS-DRG Definitions Manual. Relative weights are national factors; actual payment depends on each hospital's wage-adjusted base rate, add-ons, outliers and transfer adjustments. Nothing here is legal, clinical or billing advice; verify grouping against your encoder and the published CMS files.