2027 ICD-10-CM Diagnosis Code G71.9Primary disorder of muscle, unspecified

ICD-10-CM Codes›G00–G99›G70-G73›G71

ICD-10-CM G71.9
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G71.9 is a billable ICD-10-CM diagnosis code for primary disorder of muscle, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 91 through 93. Coders also document this condition as autosomal dominant distal hereditary motor neuropathy. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Myopathies.

G71.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the ESRD (V21) category 75 for payment year 2027.

Code Identity

ICD-10-CM Code
G71.9
Billable Status
Yes — Valid for Submission
Code Describes
Primary disorder of muscle, unspecified
Short Description
Primary disorder of muscle, unspecified
Same as the full description in the CMS dataset.
Parent Code
Primary disorders of muscles

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG70-G73Diseases of myoneural junction and muscle
CategoryG71Primary disorders of muscles
This CodeG71.9Primary disorder of muscle, unspecified

Medicare Risk Adjustment (HCC)Billing

G71.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
no payment category in the model that pays 100% of MA risk scores
Prior Model (CMS-HCC V24)
Not mapped under V24
this diagnosis newly risk-adjusts under the V28 model
Other CMS Models
ESRD (V21): HCC 75
ESRD V21 weights: 0.059 dialysis, 0.284–0.323 functioning graft
Part D (RxHCC)
Not mapped
G71.9 does not risk-adjust in the RxHCC prescription drug model

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Autosomal dominant distal hereditary motor neuropathy
  • Hereditary fibrosing poikiloderma, tendon contractures, myopathy, pulmonary fibrosis syndrome
  • Hereditary myopathy associated with hydrocephalus
  • Hereditary myopathy with early respiratory failure
  • Hereditary sclerosing poikiloderma
  • Myopathy with cytoplasmic inclusions
  • Peripheral neuropathy, myopathy, hoarseness, hearing loss syndrome
  • Proximal myopathy
  • Tendon contracture
  • X-linked myopathy with excessive autophagy

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G71.9: its own notes plus those printed at G71 and Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Hereditary myopathy NOS

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From G71 Primary disorders of muscles applies to 28 codes
  • arthrogryposis multiplex congenita (Q74.3)
  • metabolic disorders (E70-E88)
  • myositis (M60.-)
From Chapter 6 (G00-G99) Diseases of the nervous system applies to 700 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name G71.9, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming G71.9: its condition is not part of those codes, and both may be reported when the patient has both.

  • Block M60-M63 Disorders of muscles
    muscular dystrophies and myopathies (G71-G72) names G71-G72, which includes this code

Code First 1

These codes say to code first a condition named in the note, and G71.9 is one of the conditions named.

  • M62.84 Sarcopenia
    primary disorders of muscles (G71.-) names G71.-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS018
Myopathies
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Muscle Disorders

Your muscles help you move and help your body work. Different types of muscles have different jobs. There are many problems that can affect muscles. Muscle disorders can cause weakness, pain or even paralysis.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert G71.9 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
359.9 Myopathy NOS
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G71.9Overview

What is the ICD-10 code for primary disorder of muscle, unspecified?

The ICD-10-CM code for primary disorder of muscle, unspecified is G71.9 (sometimes written as G719). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G71.9 (Primary disorders of muscles) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report primary disorder of muscle, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G71.9 group to?

When primary disorder of muscle, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 91, 92, 93, with relative weights from 0.7783 to 1.7050 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of G71.9?

Under the General Equivalence Mappings, primary disorder of muscle, unspecified converts to ICD-9-CM 359.9 (myopathy NOS). The mapping is approximate, so confirm the match fits the documentation.

Does G71.9 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage: G71.9 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the ESRD (V21) category 75 (Polyneuropathy).