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MS-DRG 488 · MDC 08 · Surgical

MS-DRG 488: Knee Procedures without Principal Diagnosis of Infection with CC/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 488

FY2027 relative weight
2.2200
Higher than 68% of all MS-DRGs
Change vs FY2026
+25.5%
FY2026 weight 1.7690
Geometric mean LOS
4.6 days
Arithmetic mean 6.1 days
MDC
08
Diseases and Disorders of the Musculoskeletal System and Connective Tissue
Severity level
with CC (complication or comorbidity)
Transfer policy
Post-acute transfer DRG

TL;DR

MS-DRG 488 is a surgical group in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue) at the middle severity level of its family. CMS assigns it a FY2027 relative weight of 2.2200 with a geometric mean length of stay of 4.6 days and an arithmetic mean of 6.1. Its weight moved up 25.5% from FY2026 (1.7690). That weight is higher than 68% of all surgical and medical MS-DRGs. Its CC/MCC family (DRG 489) spans weights 1.3120 to 2.2200. The v44 Definitions Manual assigns it through 270 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 488 the FY2027 relative weight is 2.2200 against 1.7690 in FY2026, a rise of 25.49%, which exceeds the 2% threshold worth re-checking in contract models.

FY2026 versus FY2027 payment factors for MS-DRG 488
MetricFY2026FY2027Change
Relative weight1.76902.2200+0.4510
Geometric mean LOS (days)2.24.6+2.4
Arithmetic mean LOS (days)3.16.1+3.0
Weights shown are the FY2027 final values after the 10% cap on year-over-year reductions where applicable.

CC and MCC family

DRG 488 shares its base definition with 1 other MS-DRG split by severity. The family's weights span 1.3120 to 2.2200, a 1.69× spread, which is the payment effect of documenting qualifying complications and comorbidities.

MS-DRGs in the same base group as DRG 488
DRGTitleFY2027 weightGMLOS
488Knee Procedures without Principal Diagnosis of Infection with CC/MCC2.22004.6
489Knee Procedures without Principal Diagnosis of Infection without CC/MCC1.31202.0

Grouper logic (v44 Definitions Manual)

Operating Room Procedures: 270 ICD-10 codes drive assignment to this group; the first 12 are shown.

Operating Room Procedures codes assigned to DRG 488 (sample)
ICD-10 codeDescription
0M9N40ZDrainage of Right Knee Bursa and Ligament with Drainage Device, Percutaneous Endoscopic Approach
0M9P40ZDrainage of Left Knee Bursa and Ligament with Drainage Device, Percutaneous Endoscopic Approach
0MQN0ZZRepair Right Knee Bursa and Ligament, Open Approach
0MQN3ZZRepair Right Knee Bursa and Ligament, Percutaneous Approach
0MQN4ZZRepair Right Knee Bursa and Ligament, Percutaneous Endoscopic Approach
0MQP0ZZRepair Left Knee Bursa and Ligament, Open Approach
0MQP3ZZRepair Left Knee Bursa and Ligament, Percutaneous Approach
0MQP4ZZRepair Left Knee Bursa and Ligament, Percutaneous Endoscopic Approach
0MRN07ZReplacement of Right Knee Bursa and Ligament with Autologous Tissue Substitute, Open Approach
0MRN0JZReplacement of Right Knee Bursa and Ligament with Synthetic Substitute, Open Approach
0MRN0KZReplacement of Right Knee Bursa and Ligament with Nonautologous Tissue Substitute, Open Approach
0MRN47ZReplacement of Right Knee Bursa and Ligament with Autologous Tissue Substitute, Percutaneous Endoscopic Approach

Documentation and denial exposure

As a surgical DRG, assignment depends on a qualifying operating-room procedure being coded from the operative report; a missing or non-OR procedure code drops the stay into a medical DRG in MDC 08 with a lower weight. 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 488 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 488

What is MS-DRG 488?

MS-DRG 488 is "Knee Procedures without Principal Diagnosis of Infection with CC/MCC", a surgical Medicare Severity Diagnosis-Related Group in MDC 08, Diseases and Disorders of the Musculoskeletal System and Connective Tissue. 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 488?

The FY2027 relative weight is 2.2200 (IPPS final rule Table 5, effective October 1, 2026). In FY2026 it was 1.7690, a change of +25.5%.

What is the average length of stay for DRG 488?

CMS reports a geometric mean length of stay of 4.6 days and an arithmetic mean of 6.1 days for FY2027. The geometric mean is used for transfer-payment calculations.

Which DRGs are in the same CC/MCC family as 488?

DRG 489 (Knee Procedures without Principal Diagnosis of Infection without CC/MCC, weight 1.3120). The family's weights range from 1.3120 to 2.2200, so documented complications and comorbidities change payment materially.

What documentation supports the severity level of DRG 488?

DRG 488 is reached when the stay carries a secondary diagnosis from the CMS Complication or Comorbidity list but none from the MCC list. Common CC captures include chronic kidney disease stage 3 and above, uncontrolled diabetes with manifestations, malnutrition of specified severity and heart failure of a stated type. Each must be documented by the treating clinician and show clinical relevance in the record; a condition listed only in the problem list without assessment is the most frequent reason a CC is removed on audit and the stay drops to the base DRG.

Which codes group to DRG 488?

The v44 Definitions Manual lists 270 operating room procedures codes for this group. Examples from the operating room procedures list: 0M9N40Z (Drainage of Right Knee Bursa and Ligament with Drainage Device, Percutaneous Endoscopic Approach); 0M9P40Z (Drainage of Left Knee Bursa and Ligament with Drainage Device, Percutaneous Endoscopic Approach); 0MQN0ZZ (Repair Right Knee Bursa and Ligament, Open Approach); 0MQN3ZZ (Repair Right Knee Bursa and Ligament, Percutaneous Approach).

Is DRG 488 a post-acute transfer DRG?

Yes. CMS flags DRG 488 under the post-acute care transfer policy, so a discharge to a qualifying post-acute setting before the geometric mean length of stay is paid a per-diem amount rather than the full DRG payment.

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.