2027 ICD-10-CM Diagnosis Code R94.131Abnormal electromyogram [EMG]
ICD-10-CM Codes›R00–R99›R90-R94›R94
- Billable — Valid for Submission
- Not Chronic
R94.131 is a billable ICD-10-CM diagnosis code for abnormal electromyogram [EMG]. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 564 through 566. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abnormal findings without diagnosis.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Asymmetry of F-wave
- Asymmetry of H-response
- Complex repetitive EMG discharges
- Continuous motor unit activity
- Decreased frequency of F-wave
- Early recruitment of short duration polyphasic motor unit with abnormal spontaneous activity on electromyogram
- Early recruitment of short duration polyphasic motor unit without abnormal spontaneous activity on electromyogram
- Electrical EMG silence
- Electromyogram abnormal
- EMG decelerating bursts
- EMG interference pattern - finding
- EMG positive sharp waves
- Exaggeration of H-response
- F-wave finding
- High amplitude reduced interference pattern with abnormal spontaneous activity on electromyogram
- High amplitude reduced interference pattern without abnormal spontaneous activity on electromyogram
- Increased chronodispersion of F-wave
- Increased insertional activity
- Increased latency of F-wave
- Increased latency of H-response
- Increased tacheodispersion of F-wave
- Indeterminate EMG pattern
- Interference pattern showing early recruitment
- Interference pattern showing increased amplitude
- Interference pattern showing reduced amplitude
- Interference pattern showing reduced density
- Loss of H-response
- Motor unit characteristics - finding
- Motor unit morphology - finding
- Motor unit stability - finding
- Motor units with extra discharges
- Overall EMG pattern - finding
- Polyphasic units
- Polyphasic units - long duration - finding
- Polyphasic units - short duration - finding
- Reaction of degeneration by electromyogram
- Reaction of denervation by electromyogram
- Single muscle fiber finding
- Single muscle fiber jitter
- Spontaneous EMG activity
- Stable motor units
- Stalberg cloud
- Unstable motor units
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to R94.131: its own notes plus those printed at R94, block R90-R94, and Chapter 18. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- abnormal results of radionuclide [radioisotope] uptake studies
- abnormal results of scintigraphy
- nonspecific abnormal findings on diagnostic imaging by computerized axial tomography [CAT scan]
- nonspecific abnormal findings on diagnostic imaging by magnetic resonance imaging [MRI][NMR]
- nonspecific abnormal findings on diagnostic imaging by positron emission tomography [PET scan]
- nonspecific abnormal findings on diagnostic imaging by thermography
- nonspecific abnormal findings on diagnostic imaging by ultrasound [echogram]
- nonspecific abnormal findings on diagnostic imaging by X-ray examination
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- electromyogram of eye (R94.113)
- abnormal findings on antenatal screening of mother (O28.-)
- diagnostic abnormal findings classified elsewhere - see Alphabetical Index
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.
Notes
General instructions on how these codes are used.
- This chapter includes symptoms, signs, abnormal results of clinical or other investigative procedures, and ill-defined conditions regarding which no diagnosis classifiable elsewhere is recorded.
- Signs and symptoms that point rather definitely to a given diagnosis have been assigned to a category in other chapters of the classification. In general, categories in this chapter include the less well-defined conditions and symptoms that, without the necessary study of the case to establish a final diagnosis, point perhaps equally to two or more diseases or to two or more systems of the body. Practically all categories in the chapter could be designated 'not otherwise specified', 'unknown etiology' or 'transient'. The Alphabetical Index should be consulted to determine which symptoms and signs are to be allocated here and which to other chapters. The residual subcategories, numbered .8, are generally provided for other relevant symptoms that cannot be allocated elsewhere in the classification.
- The conditions and signs or symptoms included in categories R00-R94 consist of:
- (a) cases for which no more specific diagnosis can be made even after all the facts bearing on the case have been investigated;
- (b) signs or symptoms existing at the time of initial encounter that proved to be transient and whose causes could not be determined;
- (c) provisional diagnosis in a patient who failed to return for further investigation or care;
- (d) cases referred elsewhere for investigation or treatment before the diagnosis was made;
- (e) cases in which a more precise diagnosis was not available for any other reason;
- (f) certain symptoms, for which supplementary information is provided, that represent important problems in medical care in their own right.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Abnormal, abnormality, abnormalities See Also: Anomaly;
electromyogram [EMG] R94.131
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 R94.131 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About R94.131Overview
What is the ICD-10 code for abnormal electromyogram [EMG]?
The ICD-10-CM code for abnormal electromyogram [EMG] is R94.131 (sometimes written as R94131). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is R94.131 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report abnormal electromyogram [EMG] on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does R94.131 group to?
When abnormal electromyogram [EMG] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 564, 566, 565, with relative weights from 0.7374 to 1.4909 depending on complications. Higher weights mean higher Medicare reimbursement.
Can R94.131 be a principal diagnosis?
Use it with care. This is a symptom code, so once a definitive diagnosis explaining the abnormal electromyogram [EMG] is established, that condition takes the principal position instead.
Can R94.131 be reported with R94.113?
Not as a rule. The Excludes1 note on R94.131 lists "electromyogram of eye (R94.113)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
