G71.9 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · free HCC coding tools

ICD-10-CM Code View

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Code lookupG71.9

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Diseases of myoneural junction and muscle (G70-G73)

G71.9

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Primary disorder of muscle, unspecified

A primary muscle disorder where the specific type cannot be determined or is not further specified. This represents an undiagnosed or unclassified inherited muscle disease.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ESRD/PACE

N/A

—

Not risk-adjusted for this model/period.

Not mapped

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

G71Primary disorders of muscles G71.9Primary disorder of muscle, unspecified

Inclusion Terms

Official

Hereditary myopathy NOS

Excludes 2

Official

certain conditions originating in the perinatal period (P04-P96)Inherited from G00-G99, G71
certain infectious and parasitic diseases (A00-B99)Inherited from G00-G99, G71
complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from G00-G99, G71
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Inherited from G00-G99, G71
endocrine, nutritional and metabolic diseases (E00-E88)Inherited from G00-G99, G71
injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from G00-G99, G71
neoplasms (C00-D49)Inherited from G00-G99, G71
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from G00-G99, G71
arthrogryposis multiplex congenita (Q74.3)Inherited from G00-G99, G71
metabolic disorders (E70-E88)Inherited from G00-G99, G71
myositis (M60.-)Inherited from G00-G99, G71

Related Codes

Official

G71.0Muscular dystrophy G71.1Myotonic disorders G71.2Congenital myopathies G71.3Mitochondrial myopathy, not elsewhere classified G71.8Other primary disorders of muscles

Includes

Official

No Includes notes are included in this display for G71.9. Check the code and parent instructions in the Code Book.

Excludes 1

Official

No Excludes 1 notes are included in this display for G71.9. Check the code and parent instructions in the Code Book.

Code First

Official

No Code First sequencing instructions are included in this display for G71.9. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for G71.9. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for G71.9. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Use this code only when the specific primary muscle disorder cannot be identified; attempt to obtain more specific diagnosis before coding

Review medical records for any genetic testing results or muscle biopsy findings that might allow for more specific classification

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 G71.9 an HCC code?

No. G71.9 is a billable ICD-10-CM code with no mapping under the current CMS-HCC V28 community payment model, and none under the ESRD, Part D RxHCC, or HHS-HCC models.

Code: G71.9
Description: Primary disorder of muscle, unspecified
HCC (V28): No CMS-HCC V28 mapping
RAF reference coefficient: —
Billable: Yes
Payment year: 2026

Coder workflow notes

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What This Code Means

G71.9 is the ICD-10-CM diagnosis code for primary disorder of muscle, unspecified. A primary muscle disorder where the specific type cannot be determined or is not further specified. This represents an undiagnosed or unclassified inherited muscle disease. G71.9 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering diseases of myoneural junction and muscle (g70-g73).

G71.9 is a billable ICD-10-CM code, but no current CMS-HCC V28 community payment mapping is shown, and none under the ESRD, Part D RxHCC, or HHS-HCC models. Do not assign risk adjustment value from this page when no source-backed mapping is shown; verify the applicable model and payment year.

Use this code only when the specific primary muscle disorder cannot be identified; attempt to obtain more specific diagnosis before coding.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for G71.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use this code only when the specific primary muscle disorder cannot be identified; attempt to obtain more specific diagnosis before coding
•Review medical records for any genetic testing results or muscle biopsy findings that might allow for more specific classification