2027 ICD-10-CM Diagnosis Code G71.14Drug induced myotonia

ICD-10-CM Codes›G00–G99›G70-G73›G71

ICD-10-CM G71.14
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G71.14 is a billable ICD-10-CM diagnosis code for drug induced myotonia. 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 myotonia caused by drug. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Drug induced or toxic related condition and Myopathies.

G71.14 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
G71.14
Billable Status
Yes — Valid for Submission
Code Describes
Drug induced myotonia
Short Description
Drug induced myotonia
Same as the full description in the CMS dataset.
Parent Code
G71.1
Myotonic disorders

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG70-G73Diseases of myoneural junction and muscle
CategoryG71Primary disorders of muscles
This CodeG71.14Drug induced myotonia

Medicare Risk Adjustment (HCC)Billing

G71.14 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
G71.14 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.

  • Myotonia caused by drug

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G71.14: 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.

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)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

  • code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name G71.14, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming G71.14: 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 2

These codes say to code first a condition named in the note, and G71.14 is one of the conditions named.

  • H28 Cataract in diseases classified elsewhere
    myotonia (G71.1-) names G71.1-, which includes this code
  • 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 INJ030
Drug induced or toxic related condition
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR NVS018
Myopathies
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • Myotonic Disorders

    diseases characterized by myotonia, which may be inherited or acquired. myotonia may be restricted to certain muscles (e.g., intrinsic hand muscles) or occur as a generalized condition.

Patient EducationClinical

Drug Reactions

Most of the time, medicines make our lives better. They reduce aches and pains, fight infections, and control problems such as high blood pressure or diabetes. But medicines can also cause unwanted reactions, such as drug interactions, side effects, and allergies.

The full article covers:

  • What is a drug interaction?
  • What are side effects?
  • What are drug allergies?
  • How can I stay safe when taking medicines?

Read the full article at MedlinePlus

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

Convert G71.14 to ICD-9-CMHistory

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

ICD-9-CM
359.24 Drug induced myotonia
Exact Match The mapping is direct, with no qualifiers.

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 G71.14Overview

What is the ICD-10 code for drug induced myotonia?

The ICD-10-CM code for drug induced myotonia is G71.14 (sometimes written as G7114). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G71.14 (Myotonic disorders) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report drug induced myotonia on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G71.14 group to?

When drug induced myotonia 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.

Does G71.14 need an additional code?

When the condition applies, yes. The Use Additional Code note reads: code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5). The additional code is reported after G71.14.

What is the ICD-9 equivalent of G71.14?

Under the General Equivalence Mappings, drug induced myotonia converts to ICD-9-CM 359.24 (drug induced myotonia). The mapping is a direct match.

Does G71.14 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage: G71.14 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the ESRD (V21) category 75 (Polyneuropathy).