M35.81

Billable code

Multisystem inflammatory syndrome

The ICD-10 code for multisystem inflammatory syndrome is M35.81.

Clinical notes

Code also

Two codes may be needed to fully describe a condition, but unlike Code First/Use Additional Code, the sequencing order is not mandated by convention.

any associated complications such as:
acute hepatic failure (K72.0-)
acute kidney failure (N17.-)
acute myocarditis (I40.-)
acute respiratory distress syndrome (J80)
cardiac arrhythmia (I47-I49.-)
pneumonia due to COVID-19 (J12.82)
severe sepsis (R65.2-)
viral cardiomyopathy (B33.24)
viral pericarditis (B33.23)

Code first

This code represents a manifestation of an underlying disease. Coding convention requires the underlying (etiology) code to be sequenced first, with this code listed second.

, if applicable, COVID-19 (U07.1)

Also known as

Alternate wording, synonyms, or specific conditions that fall under this code, listed to help confirm you've picked the right one.

MIS-A
MIS-C
Multisystem inflammatory syndrome in adults
Multisystem inflammatory syndrome in children
Pediatric inflammatory multisystem syndrome
PIMS

Use additional code

This code represents an underlying condition. When a related manifestation is also present, coding convention calls for an additional code to be listed after this one.

code, if applicable, for:
exposure to COVID-19 or SARS-CoV-2 infection (Z20.822)
personal history of COVID-19 (Z86.16)
post COVID-19 condition (U09.9)

Documentation support

General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.

•This code represents a manifestation. Documentation should identify the underlying condition, which must be coded first.
•If the associated manifestation or related condition noted above is also documented, an additional code should be reported alongside this one.
•As a general rule, code to the highest level of specificity supported by the documentation in the medical record.

Related codes in this category

M35.89Other specified systemic involvement of connective tissue
M35.81Multisystem inflammatory syndrome

Associated MS-DRGs

M35.81 can serve as the principal diagnosis for these Medicare Severity Diagnosis-Related Groups.

Informational only — actual DRG assignment also depends on procedures, complications/comorbidities (CC/MCC), discharge status, and payer-specific rules not reflected here.