2026 ICD-10-CM Diagnosis Code M30.3

Mucocutaneous lymph node syndrome [Kawasaki]

ICD-10-CM Code:
M30.3
ICD-10 Code for:
Mucocutaneous lymph node syndrome [Kawasaki]
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Chronic
Code Navigator:

M30.3 is a billable diagnosis code used to specify a medical diagnosis of mucocutaneous lymph node syndrome [kawasaki]. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026.

Code Classification

  • Diseases of the musculoskeletal system and connective tissue
    M00–M99
    • Systemic connective tissue disorders
      M30-M36
      • Polyarteritis nodosa and related conditions
        M30

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

  • Acute febrile mucocutaneous lymph node syndrome
  • Aneurysm of coronary artery due to and following acute febrile mucocutaneous lymph node syndrome
  • Aneurysm of coronary vessels
  • Myocarditis due to Kawasaki disease
  • Primary systemic arteritis
  • Vasculitis of medium sized vessel

Clinical Classification

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

Systemic lupus erythematosus and connective tissue disorders

CCSR Code: MUS024

Inpatient Default: Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

Vasculitis

CCSR Code: CIR037

Inpatient Default: N - Not default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: N - Not default outpatient assignment for principal diagnosis or first-listed diagnosis.

Clinical Information

  • Mucocutaneous Lymph Node Syndrome

    an acute, febrile, mucocutaneous condition accompanied by swelling of cervical lymph nodes in infants and young children. the principal symptoms are fever, congestion of the ocular conjunctivae, reddening of the lips and oral cavity, protuberance of tongue papillae, and edema or erythema of the extremities.

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Index of External Cause of Injuries

References found for this diagnosis code in the External Cause of Injuries Index:

    • Kawasaki's syndrome
    • Syndrome
      • mucocutaneous lymph node (acute febrile) (MCLS)

Convert M30.3 to ICD-9-CM

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

Mucocutan lymph node syn

ICD-9-CM: 446.1

This is a direct match with no additional mapping qualifiers. The absence of a flag generally means the mapping is considered exact or precise. In other words, the ICD-10 code maps cleanly to the ICD-9 code without qualification, approximation, or needing multiple codes.

Patient Education


Kawasaki Disease

What is Kawasaki disease?

Kawasaki disease is a rare illness that usually affects small children. Other names for the disease are Kawasaki syndrome and mucocutaneous lymph node syndrome. It is a type of vasculitis, which is inflammation of the blood vessels. Kawasaki disease is serious, but most children can fully recover if they are treated right away.

What causes Kawasaki disease?

Kawasaki disease happens when the immune system injures the blood vessels by mistake. Researchers do not fully know why this happens. But when it does, the blood vessels become inflamed and can narrow or close off.

Genetics may play a role in Kawasaki disease. There may also be environmental factors, such as infections. It does not seem to be contagious. This means that it cannot be passed from one child to another.

Who is more likely to develop Kawasaki disease?

Kawasaki disease usually affects children under the age of 5. But older children and adults can sometimes get it. It is more common in boys than girls. It can affect children of any race, but those with Asian or Pacific Islander descent are more likely to get it.

What are the symptoms of Kawasaki disease?

The symptoms of Kawasaki disease may include:

  • High fever lasting at least five days
  • A rash, often on the back, chest, and groin
  • Swollen hands and feet
  • Redness of the lips, lining of the mouth, tongue, palms of the hand, and soles of the feet
  • Pink eye (conjunctivitis)
  • Swollen lymph nodes in the neck

Contact your child's health care provider if your child has a fever for 4 days, especially if they have any other symptoms of Kawasaki disease.

What other problems can Kawasaki disease cause?

Sometimes Kawasaki disease can affect the walls of the coronary arteries. These arteries bring blood and oxygen to your heart. This can lead to:

  • An aneurysm (bulging and thinning of the walls of the arteries). This can raise the risk of blood clots in the arteries. If the blood clots are not treated, they could lead to a heart attack or internal bleeding.
  • Inflammation in the heart.
  • Heart valve problems.

Kawasaki disease can also affect other parts of the body, including the brain and nervous system, the immune system, and the digestive system.

How is Kawasaki disease diagnosed?

There is no specific test for Kawasaki disease. To find out if your child has Kawasaki disease, your child's provider:

  • Will do a physical exam, which includes looking at the signs and symptoms
  • Will likely order blood and urine tests to rule out other diseases and check for signs of inflammation
  • May order tests to check for damage to the heart, such as an echocardiogram and electrocardiogram (EKG)

What are the treatments for Kawasaki disease?

Kawasaki disease is usually treated in the hospital with an intravenous (IV) dose of immunoglobulin (IVIG) antibodies. Antibodies are proteins that your immune system makes to fight infections.

Aspirin may also be part of the treatment. But do not give your child aspirin unless the health care provider tells you to. Aspirin can cause Reye syndrome in children. This is a rare, serious illness that can affect the brain and liver.

Treatment usually works. But if it is not working well enough, the provider may also give your child other medicines to fight the inflammation. If the disease affects your child's heart, they might need additional medicines, surgery, or other medical procedures.


[Learn More in MedlinePlus]

Kawasaki disease

Kawasaki disease is a sudden and time-limited (acute) illness that affects infants and young children. Affected children develop a prolonged fever lasting several days, a skin rash, and swollen lymph nodes in the neck (cervical lymphadenopathy). They also develop redness in the whites of the eyes (conjunctivitis) and redness (erythema) of the lips, lining of the mouth (oral mucosa), tongue, palms of the hands, and soles of the feet.

Without treatment, 15 to 25 percent of individuals with Kawasaki disease develop bulging and thinning of the walls of the arteries that supply blood to the heart muscle (coronary artery aneurysms) or other damage to the coronary arteries, which can be life-threatening.


[Learn More in MedlinePlus]

Code History

  • FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026
  • FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025
  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.

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.