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MS-DRG 923 · MDC 21 · Medical

MS-DRG 923: Other Injury, Poisoning and Toxic Effect Diagnoses without MCC

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 923

FY2027 relative weight
0.9980
Higher than 22% of all MS-DRGs
Change vs FY2026
-2.0%
FY2026 weight 1.0180
Geometric mean LOS
2.9 days
Arithmetic mean 4.5 days
MDC
21
Assignment of Diagnosis Codes
Severity level
without MCC
Transfer policy
Not a transfer DRG

TL;DR

MS-DRG 923 is a medical group in MDC 21 (Assignment of Diagnosis Codes) at the base severity level of its family. CMS assigns it a FY2027 relative weight of 0.9980 with a geometric mean length of stay of 2.9 days and an arithmetic mean of 4.5. Its weight moved down 2.0% from FY2026 (1.0180). That weight is higher than 22% of all medical and surgical MS-DRGs. Its CC/MCC family (DRG 922) spans weights 0.9980 to 1.6250. The v44 Definitions Manual assigns it through 2446 principal diagnosis codes.

What changed from FY2026 to FY2027

CMS recalibrates every MS-DRG weight annually from the prior year's MedPAR claims. For DRG 923 the FY2027 relative weight is 0.9980 against 1.0180 in FY2026, a fall of 1.96%.

FY2026 versus FY2027 payment factors for MS-DRG 923
MetricFY2026FY2027Change
Relative weight1.01800.9980-0.0200
Geometric mean LOS (days)2.82.9+0.1
Arithmetic mean LOS (days)4.44.5+0.1
Weights shown are the FY2027 final values after the 10% cap on year-over-year reductions where applicable.

CC and MCC family

DRG 923 shares its base definition with 1 other MS-DRG split by severity. The family's weights span 0.9980 to 1.6250, a 1.63× spread, which is the payment effect of documenting qualifying complications and comorbidities.

MS-DRGs in the same base group as DRG 923
DRGTitleFY2027 weightGMLOS
922Other Injury, Poisoning and Toxic Effect Diagnoses with MCC1.62503.9
923Other Injury, Poisoning and Toxic Effect Diagnoses without MCC0.99802.9

Grouper logic (v44 Definitions Manual)

Principal Diagnosis: 2446 ICD-10 codes drive assignment to this group; the first 12 are shown.

Principal Diagnosis codes assigned to DRG 923 (sample)
ICD-10 codeDescription
M9701XSPeriprosthetic fracture around internal prosthetic right hip joint, sequela
M9702XSPeriprosthetic fracture around internal prosthetic left hip joint, sequela
M9711XSPeriprosthetic fracture around internal prosthetic right knee joint, sequela
M9712XSPeriprosthetic fracture around internal prosthetic left knee joint, sequela
M9721XSPeriprosthetic fracture around internal prosthetic right ankle joint, sequela
M9722XSPeriprosthetic fracture around internal prosthetic left ankle joint, sequela
M9731XSPeriprosthetic fracture around internal prosthetic right shoulder joint, sequela
M9732XSPeriprosthetic fracture around internal prosthetic left shoulder joint, sequela
M9741XSPeriprosthetic fracture around internal prosthetic right elbow joint, sequela
M9742XSPeriprosthetic fracture around internal prosthetic left elbow joint, sequela
M978XXSPeriprosthetic fracture around other internal prosthetic joint, sequela
M979XXSPeriprosthetic fracture around unspecified internal prosthetic joint, sequela

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 splits by severity, auditors target CC and MCC capture: each secondary diagnosis must be documented as present, monitored, evaluated or treated during the stay to survive a DRG-validation review. 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 923 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.

Frequently asked questions — DRG 923

What is MS-DRG 923?

MS-DRG 923 is "Other Injury, Poisoning and Toxic Effect Diagnoses without MCC", a medical Medicare Severity Diagnosis-Related Group in MDC 21, Assignment of Diagnosis Codes. 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 923?

The FY2027 relative weight is 0.9980 (IPPS final rule Table 5, effective October 1, 2026). In FY2026 it was 1.0180, a change of -2.0%.

What is the average length of stay for DRG 923?

CMS reports a geometric mean length of stay of 2.9 days and an arithmetic mean of 4.5 days for FY2027. The geometric mean is used for transfer-payment calculations.

Which DRGs are in the same CC/MCC family as 923?

DRG 922 (Other Injury, Poisoning and Toxic Effect Diagnoses with MCC, weight 1.6250). The family's weights range from 0.9980 to 1.6250, so documented complications and comorbidities change payment materially.

What documentation supports the severity level of DRG 923?

DRG 923 is the base-severity assignment: no secondary diagnosis on the CC or MCC lists was coded, or the only ones present are excluded for this principal diagnosis. Revenue-integrity review here looks for undercapture, meaning conditions treated during the stay (electrolyte disorders, specified anemia, acute blood loss, pressure injuries present on admission) that were never documented to the specificity the lists require. A compliant query to the attending, not a coder assumption, is the only way to move a stay to the CC or MCC sibling.

Which codes group to DRG 923?

The v44 Definitions Manual lists 2446 principal diagnosis codes for this group. Examples from the principal diagnosis list: M9701XS (Periprosthetic fracture around internal prosthetic right hip joint, sequela); M9702XS (Periprosthetic fracture around internal prosthetic left hip joint, sequela); M9711XS (Periprosthetic fracture around internal prosthetic right knee joint, sequela); M9712XS (Periprosthetic fracture around internal prosthetic left knee joint, sequela).

Is DRG 923 a post-acute transfer DRG?

No. DRG 923 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.