M35.81
Multisystem inflammatory syndrome
Billable FY2026 2025-10-01 → 2026-09-30
Exclusions 12 never code together
M30-M36block
Excludes1
- autoimmune disease, single organ or single cell-type -code to relevant condition category
M00-M99chapter
Excludes2
- arthropathic psoriasis (L40.5-)L40.5-
- certain conditions originating in the perinatal period (P04-P96)P04-P96
- certain infectious and parasitic diseases (A00-B99)A00-B99
- compartment syndrome (traumatic) (T79.A-)T79.A-
- complications of pregnancy, childbirth and the puerperium (O00-O9A)O00-O9A
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Q00-Q99
- endocrine, nutritional and metabolic diseases (E00-E88)E00-E88
- injury, poisoning and certain other consequences of external causes (S00-T88)S00-T88
- neoplasms (C00-D49)C00-D49
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)R00-R94
Excludes1 — never code together. The excluded condition and this one are mutually exclusive.
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes 26
M35.81code
Inclusion terms
- MIS-A
- MIS-C
- Multisystem inflammatory syndrome in adults
- Multisystem inflammatory syndrome in children
- Pediatric inflammatory multisystem syndrome
- PIMS
Code first
- , if applicable, COVID-19 (U07.1)U07.1
Use additional code
Code also
- any associated complications such as:
- acute hepatic failure (K72.0-)K72.0-
- acute kidney failure (N17.-)N17.-
- acute myocarditis (I40.-)I40.-
- acute respiratory distress syndrome (J80)J80
- cardiac arrhythmia (I47-I49.-)I47-I49
- pneumonia due to COVID-19 (J12.82)J12.82
- severe sepsis (R65.2-)R65.2-
- viral cardiomyopathy (B33.24)B33.24
- viral pericarditis (B33.23)B33.23
M30-M36block
Includes
- autoimmune disease NOS
- collagen (vascular) disease NOS
- systemic autoimmune disease
- systemic collagen (vascular) disease
M00-M99chapter
Notes
- Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
Index entries leading here 6
Alongside this code 1 same parent — M35.8
Medications 1
MED-RT files conditions by MeSH, which carves the world differently from ICD-10. These are name matches on this code's description, offered as candidates — not as an assertion that they are this code.
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.