Skip to main content
MS-DRG 545 · MDC 08 · Medical

MS-DRG 545: Connective Tissue Disorders with 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 545

FY2027 relative weight
2.3900
Higher than 71% of all MS-DRGs
Change vs FY2026
-3.7%
FY2026 weight 2.4820
Geometric mean LOS
5.3 days
Arithmetic mean 7.7 days
MDC
08
Diseases and Disorders of the Musculoskeletal System and Connective Tissue
Severity level
with MCC (major complication or comorbidity)
Transfer policy
Post-acute transfer DRG

TL;DR

MS-DRG 545 is a medical group in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue) at the highest-severity level of its family. CMS assigns it a FY2027 relative weight of 2.3900 with a geometric mean length of stay of 5.3 days and an arithmetic mean of 7.7. Its weight moved down 3.7% from FY2026 (2.4820). That weight is higher than 71% of all medical and surgical MS-DRGs. Its CC/MCC family (DRG 546, DRG 547) spans weights 0.7530 to 2.3900. The v44 Definitions Manual assigns it through 562 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 545 the FY2027 relative weight is 2.3900 against 2.4820 in FY2026, a fall of 3.71%, which exceeds the 2% threshold worth re-checking in contract models.

FY2026 versus FY2027 payment factors for MS-DRG 545
MetricFY2026FY2027Change
Relative weight2.48202.3900-0.0920
Geometric mean LOS (days)5.55.3-0.2
Arithmetic mean LOS (days)8.37.7-0.6
Weights shown are the FY2027 final values after the 10% cap on year-over-year reductions where applicable.

CC and MCC family

DRG 545 shares its base definition with 2 other MS-DRGs split by severity. The family's weights span 0.7530 to 2.3900, a 3.17× spread, which is the payment effect of documenting qualifying complications and comorbidities.

MS-DRGs in the same base group as DRG 545
DRGTitleFY2027 weightGMLOS
545Connective Tissue Disorders with MCC2.39005.3
546Connective Tissue Disorders with CC1.17303.3
547Connective Tissue Disorders without CC/MCC0.75302.3

Grouper logic (v44 Definitions Manual)

Principal Diagnosis: 562 ICD-10 codes drive assignment to this group; the first 12 are shown.

Principal Diagnosis codes assigned to DRG 545 (sample)
ICD-10 codeDescription
D8982Autoimmune lymphoproliferative syndrome [ALPS]
E850Non-neuropathic heredofamilial amyloidosis
E851Neuropathic heredofamilial amyloidosis
E852Heredofamilial amyloidosis, unspecified
E853Secondary systemic amyloidosis
E854Organ-limited amyloidosis
E8581Light chain (AL) amyloidosis
E8582Wild-type transthyretin-related (ATTR) amyloidosis
E8589Other amyloidosis
E859Amyloidosis, unspecified
G7241Inclusion body myositis [IBM]
G7249Other inflammatory and immune myopathies, not elsewhere classified

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 545 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 545

What is MS-DRG 545?

MS-DRG 545 is "Connective Tissue Disorders with MCC", a medical 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 545?

The FY2027 relative weight is 2.3900 (IPPS final rule Table 5, effective October 1, 2026). In FY2026 it was 2.4820, a change of -3.7%.

What is the average length of stay for DRG 545?

CMS reports a geometric mean length of stay of 5.3 days and an arithmetic mean of 7.7 days for FY2027. The geometric mean is used for transfer-payment calculations.

Which DRGs are in the same CC/MCC family as 545?

DRG 546 (Connective Tissue Disorders with CC, weight 1.1730); DRG 547 (Connective Tissue Disorders without CC/MCC, weight 0.7530). The family's weights range from 0.7530 to 2.3900, so documented complications and comorbidities change payment materially.

What documentation supports the severity level of DRG 545?

DRG 545 requires at least one secondary diagnosis on the CMS Major Complication or Comorbidity list, documented as present and clinically addressed during the stay (monitored, evaluated, treated or extending the stay). Conditions such as acute respiratory failure, severe sepsis or acute kidney injury with specified cause qualify only when the attending's note states the diagnosis itself, not just the lab values. Recovery auditors downgrade this group to the CC or base level when the MCC rests on an unconfirmed query or a resolved historical condition, so the query response and the discharge summary must agree.

Which codes group to DRG 545?

The v44 Definitions Manual lists 562 principal diagnosis codes for this group. Examples from the principal diagnosis list: D8982 (Autoimmune lymphoproliferative syndrome [ALPS]); E850 (Non-neuropathic heredofamilial amyloidosis); E851 (Neuropathic heredofamilial amyloidosis); E852 (Heredofamilial amyloidosis, unspecified).

Is DRG 545 a post-acute transfer DRG?

Yes. CMS flags DRG 545 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.