M79.A19 ICD-10-CM Code: Nontraumatic compartment syndrome of unspecified upper extremity
HCC Buddy Code Card
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FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Other soft tissue disorders (M70-M79)
M79.A19
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceNontraumatic compartment syndrome of unspecified upper extremity
A serious condition where pressure builds up in the muscle compartments of an arm (side not specified) without trauma, potentially restricting blood flow and damaging tissues.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
N/A—
Not mapped
ACA/HHS
N/A—
Not mapped
ESRD/PACE
N/A—
Not mapped
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
Official- Nontraumatic compartment syndrome of shoulder, arm, forearm, wrist, hand, and fingers
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for M79.A19 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for M79.A19 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for M79.A19 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for M79.A19 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for M79.A19 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for M79.A19 in this effective period.
Buddy Documentation Tip
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is M79.A19 an HCC code?
No. M79.A19 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
- Code
- M79.A19
- Description
- Nontraumatic compartment syndrome of unspecified upper extremity
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF
- —
- Billable
- Yes
- Payment year
- 2026
Coder workflow notes
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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
M79.A19 is the ICD-10-CM diagnosis code for nontraumatic compartment syndrome of unspecified upper extremity. A serious condition where pressure builds up in the muscle compartments of an arm (side not specified) without trauma, potentially restricting blood flow and damaging tissues. M79.A19 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering other soft tissue disorders (m70-m79).
M79.A19 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Use this code only when the specific arm (right or left) is not documented.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for M79.A19 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.