G70.81Lambert-Eaton syndrome in disease classified elsewhere

G70.81 is the ICD-10-CM diagnosis code for Lambert-Eaton syndrome in disease classified elsewhere. It belongs to category G70 (myasthenia gravis and other myoneural disorders), block G70-G73 (diseases of myoneural junction and muscle) and chapter 6 (diseases of the nervous system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within G70.8 (other specified myoneural disorders), G70.81 is specifically for Lambert-Eaton syndrome in disease classified elsewhere. Related codes cover Lambert-Eaton syndrome, unspecified (G70.80) and other specified myoneural disorders (G70.89).

Don't report G70.81 together with the conditions in its Excludes1 note: Lambert-Eaton syndrome in neoplastic disease (G73.1).

Code first: underlying disease.

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 056 (Degenerative Nervous System Disorders with MCC, relative weight 2.2655) and DRG 057 (Degenerative Nervous System Disorders without MCC, relative weight 1.2838), in MDC 01 (Diseases and Disorders of the Nervous System), 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 is a manifestation code, so it describes the effect of an underlying disease and can't be the principal diagnosis. Code the underlying condition first.

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 358.39 (Lambert-Eaton syndrome in other diseases classified elsewhere).