2026 ICD-10-CM Diagnosis Code G70.81Lambert-Eaton syndrome in disease classified elsewhere
ICD-10-CM Codes›G00–G99›G70-G73›G70
- Billable — Valid for Submission
- Chronic Condition
G70.81 is a billable ICD-10-CM diagnosis code for Lambert-Eaton syndrome in disease classified elsewhere. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is a manifestation code that cannot be reported as the principal diagnosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Myopathies.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for G70.81.
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Code First
- underlying disease
Type 1 Excludes
- Lambert-Eaton syndrome in neoplastic disease G73.1
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Syndrome - See Also: Disease;
- Lambert-Eaton - G70.80
- in
- specified disease NEC - G70.81
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Syndrome
- Lambert-Eaton
- in
- specified disease NEC
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Autoimmune Diseases
Your immune system protects you from disease and infection by attacking germs that get into your body, such as viruses and bacteria. Your immune system can tell that the germs aren't part of you, so it destroys them. If you have an autoimmune disease, your immune system attacks the healthy cells of your organs and tissues by mistake.
The full article covers:
- What are autoimmune diseases?
- What causes autoimmune diseases?
- Who is at risk for autoimmune diseases?
- What are the symptoms of autoimmune diseases?
- How are autoimmune diseases diagnosed?
- What are the treatments for autoimmune diseases?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert G70.81 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About G70.81Overview
Is G70.81 (Other specified myoneural disorders) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report Lambert-Eaton syndrome in disease classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Can G70.81 be a principal diagnosis?
No. This is a manifestation code: Lambert-Eaton syndrome in disease classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
What is the ICD-9 equivalent of G70.81?
Under the General Equivalence Mappings, Lambert-Eaton syndrome in disease classified elsewhere converts to ICD-9-CM 358.39 (Lambert-Eaton syn ot dis). The mapping is a direct match.
Footnotes
[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:
- The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
- The condition places limitations on self-care, independent living, and social interactions.
