G73.3 - Myasthenic syndromes in other diseases classified elsewhere

Version 2023
Billable Code
Manifestation Diagnoses
Convert to ICD-9
ICD-10:G73.3
Short Description:Myasthenic syndromes in other diseases classified elsewhere
Long Description:Myasthenic syndromes in other diseases classified elsewhere
Status: Valid for Submission
Version:ICD-10-CM 2023
Code Classification:
  • Diseases of the nervous system (G00–G99)
    • Diseases of myoneural junction and muscle (G70-G73)
      • Disord of myoneural junction and muscle in dis classd elswhr (G73)

G73.3 is a billable ICD-10 code used to specify a medical diagnosis of myasthenic syndromes in other diseases classified elsewhere. The code is valid during the fiscal year 2023 from October 01, 2022 through September 30, 2023 for the submission of HIPAA-covered transactions.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more. The following references are applicable to this diagnosis code:


Code First

Code First
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.

Code Edits

The Medicare Code Editor (MCE) detects and reports errors in the coding of claims data. The following ICD-10 Code Edits are applicable to this code:

Convert to ICD-9 Code

Source ICD-10 CodeTarget ICD-9 Code
G73.3358.1 - Myasthenia in oth dis

Patient Education


Myasthenia Gravis

Myasthenia gravis is a disease that causes weakness in your voluntary muscles. These are the muscles that you control. For example, you may have weakness in the muscles for eye movement, facial expressions, and swallowing. You can also have weakness in other muscles. This weakness gets worse with activity, and better with rest.

Myasthenia gravis is an autoimmune disease. Your body's immune system makes antibodies that block or change some of the nerve signals to your muscles. This makes your muscles weaker.

Other conditions can cause muscle weakness, so myasthenia gravis can be hard to diagnose. Tests used to make a diagnosis include blood, nerve, muscle, and imaging tests.

With treatment, the muscle weakness often gets much better. Medicines can help improve nerve-to-muscle messages and make muscles stronger. Other drugs keep your body from making so many abnormal antibodies. These medicines can have major side effects, so they should be used carefully. There are also treatments which filter abnormal antibodies from the blood or add healthy antibodies from donated blood. Sometimes, surgery to take out the thymus gland helps.

Some people with myasthenia gravis go into remission. This means that they do not have symptoms. The remission is usually temporary, but sometimes it can be permanent.

NIH: National Institute of Neurological Disorders and Stroke


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Code History

Previous Code: G73.1

Parent Code: G73

Next Code: G73.7