R94.131Abnormal electromyogram [EMG]

R94.131 is the ICD-10-CM diagnosis code for abnormal electromyogram [EMG]. It belongs to category R94 (abnormal results of function studies), block R90-R94 (abnormal findings on diagnostic imaging and in function studies, without diagnosis) and chapter 18 (symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within R94.13 (abnormal results of function studies of peripheral nervous system), R94.131 is specifically for abnormal electromyogram [EMG]. Related codes cover response to nerve stimulation, unspecified (R94.130) and results of other function studies of peripheral nervous system (R94.138).

Don't report R94.131 together with the conditions in its Excludes1 note: electromyogram of eye (R94.113).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 564 (Other Musculoskeletal System and Connective Tissue Diagnoses with MCC, relative weight 1.4908), DRG 565 (Other Musculoskeletal System and Connective Tissue Diagnoses with CC, relative weight 0.9783) and DRG 566 (Other Musculoskeletal System and Connective Tissue Diagnoses without CC/MCC, relative weight 0.7378), in MDC 08 (Diseases and Disorders of the Musculoskeletal System and Connective Tissue), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 794.17 (nonspecific abnormal electromyogram [EMG]).