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MS-DRG 155 · MDC 03 · Medical

MS-DRG 155: Other Ear, Nose, Mouth and Throat Diagnoses with CC

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 155

FY2027 relative weight
0.9320
Higher than 19% of all MS-DRGs
Change vs FY2026
+1.8%
FY2026 weight 0.9160
Geometric mean LOS
2.8 days
Arithmetic mean 3.5 days
MDC
03
Assignment of Diagnosis Codes
Severity level
with CC (complication or comorbidity)
Transfer policy
Not a transfer DRG

TL;DR

MS-DRG 155 is a medical group in MDC 03 (Assignment of Diagnosis Codes) at the middle severity level of its family. CMS assigns it a FY2027 relative weight of 0.9320 with a geometric mean length of stay of 2.8 days and an arithmetic mean of 3.5. Its weight moved up 1.8% from FY2026 (0.9160). That weight is higher than 19% of all medical and surgical MS-DRGs. Its CC/MCC family (DRG 154, DRG 156) spans weights 0.6660 to 1.5920. The v44 Definitions Manual assigns it through 660 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 155 the FY2027 relative weight is 0.9320 against 0.9160 in FY2026, a rise of 1.75%.

FY2026 versus FY2027 payment factors for MS-DRG 155
MetricFY2026FY2027Change
Relative weight0.91600.9320+0.0160
Geometric mean LOS (days)2.82.8+0.0
Arithmetic mean LOS (days)3.53.5+0.0
Weights shown are the FY2027 final values after the 10% cap on year-over-year reductions where applicable.

CC and MCC family

DRG 155 shares its base definition with 2 other MS-DRGs split by severity. The family's weights span 0.6660 to 1.5920, a 2.39× spread, which is the payment effect of documenting qualifying complications and comorbidities.

MS-DRGs in the same base group as DRG 155
DRGTitleFY2027 weightGMLOS
154Other Ear, Nose, Mouth and Throat Diagnoses with MCC1.59204.0
155Other Ear, Nose, Mouth and Throat Diagnoses with CC0.93202.8
156Other Ear, Nose, Mouth and Throat Diagnoses without CC/MCC0.66602.1

Grouper logic (v44 Definitions Manual)

Principal Diagnosis: 660 ICD-10 codes drive assignment to this group; the first 12 are shown.

Principal Diagnosis codes assigned to DRG 155 (sample)
ICD-10 codeDescription
A186Tuberculosis of (inner) (middle) ear
A360Pharyngeal diphtheria
A361Nasopharyngeal diphtheria
A362Laryngeal diphtheria
A665Gangosa
B001Herpesviral vesicular dermatitis
B3784Candidal otitis externa
D104Benign neoplasm of tonsil
D105Benign neoplasm of other parts of oropharynx
D106Benign neoplasm of nasopharynx
D107Benign neoplasm of hypopharynx
D109Benign neoplasm of pharynx, unspecified

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 155 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 155

What is MS-DRG 155?

MS-DRG 155 is "Other Ear, Nose, Mouth and Throat Diagnoses with CC", a medical Medicare Severity Diagnosis-Related Group in MDC 03, 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 155?

The FY2027 relative weight is 0.9320 (IPPS final rule Table 5, effective October 1, 2026). In FY2026 it was 0.9160, a change of +1.8%.

What is the average length of stay for DRG 155?

CMS reports a geometric mean length of stay of 2.8 days and an arithmetic mean of 3.5 days for FY2027. The geometric mean is used for transfer-payment calculations.

Which DRGs are in the same CC/MCC family as 155?

DRG 154 (Other Ear, Nose, Mouth and Throat Diagnoses with MCC, weight 1.5920); DRG 156 (Other Ear, Nose, Mouth and Throat Diagnoses without CC/MCC, weight 0.6660). The family's weights range from 0.6660 to 1.5920, so documented complications and comorbidities change payment materially.

What documentation supports the severity level of DRG 155?

DRG 155 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 155?

The v44 Definitions Manual lists 660 principal diagnosis codes for this group. Examples from the principal diagnosis list: A186 (Tuberculosis of (inner) (middle) ear); A360 (Pharyngeal diphtheria); A361 (Nasopharyngeal diphtheria); A362 (Laryngeal diphtheria).

Is DRG 155 a post-acute transfer DRG?

No. DRG 155 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.