2026 ICD-10-CM Diagnosis Code M30.3Mucocutaneous lymph node syndrome [Kawasaki]
ICD-10-CM Codes›M00–M99›M30-M36›M30
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 93
- Chronic Condition
M30.3 is a billable ICD-10-CM diagnosis code for mucocutaneous lymph node syndrome [Kawasaki]. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 545 through 547. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 19 closely related codes. Coders also document this condition as acute febrile mucocutaneous lymph node syndrome. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Systemic lupus erythematosus and connective tissue disorders and Vasculitis.
For Medicare Advantage risk adjustment, M30.3 maps to CMS-HCC Category 93 (Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders) under the V28 model, adding a risk factor of about 0.617 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
M30.3 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- 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
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Kawasaki's syndrome M30.3
Syndrome See Also: Disease;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
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.
Patient EducationClinical
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.
The full article covers:
- What is Kawasaki disease?
- What causes Kawasaki disease?
- Who is more likely to develop Kawasaki disease?
- What are the symptoms of Kawasaki disease?
- What other problems can Kawasaki disease cause?
- How is Kawasaki disease diagnosed?
- What are the treatments for Kawasaki disease?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert M30.3 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About M30.3Overview
What is the ICD-10 code for mucocutaneous lymph node syndrome [Kawasaki]?
The ICD-10-CM code for mucocutaneous lymph node syndrome [Kawasaki] is M30.3 (sometimes written as M303). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is M30.3 (Polyarteritis nodosa and related conditions) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report mucocutaneous lymph node syndrome [Kawasaki] on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does M30.3 group to?
When mucocutaneous lymph node syndrome [Kawasaki] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 545, 546, 547, with relative weights from 0.8362 to 2.4817 depending on complications. Higher weights mean higher Medicare reimbursement.
Is M30.3 a CC or MCC?
CMS lists M30.3 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 19 closely related codes in its exclusion list.
What is the ICD-9 equivalent of M30.3?
Under the General Equivalence Mappings, mucocutaneous lymph node syndrome [Kawasaki] converts to ICD-9-CM 446.1 (mucocutan lymph node syn). The mapping is a direct match.
What HCC is M30.3?
M30.3 (mucocutaneous lymph node syndrome [Kawasaki]) maps to CMS-HCC Category 93 (Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders), commonly written as HCC 93, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 40 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 84.
Does M30.3 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, M30.3 adds a risk adjustment factor of about 0.617 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.288 to 0.617 depending on the payment segment). HCC 93 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 93 category page.
