2022 ICD-10-CM Diagnosis Code M35.81

Multisystem inflammatory syndrome

    2021 - New Code 2022 Billable/Specific Code
  • M35.81 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2022 edition of ICD-10-CM M35.81 became effective on October 1, 2021.
  • This is the American ICD-10-CM version of M35.81 - other international versions of ICD-10 M35.81 may differ.
Applicable To
  • MIS-A
  • MIS-C
  • Multisystem inflammatory syndrome in adults
  • Multisystem inflammatory syndrome in children
  • Pediatric inflammatory multisystem syndrome
  • PIMS
Use Additional
Use Additional Help
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. In most cases the manifestation codes will have in the code title, "in diseases classified elsewhere." Codes with this title are a component of the etiology/manifestation convention. The code title indicates that it is a manifestation code. "In diseases classified elsewhere" codes are never permitted to be used as first listed or principle diagnosis codes. They must be used in conjunction with an underlying condition code and they must be listed following the underlying condition.
  • code, if applicable, for:
  • exposure to COVID-19 or SARS-CoV-2 infection (
    ICD-10-CM Diagnosis Code Z20.822

    Contact with and (suspected) exposure to COVID-19

      2016 2017 2018 2019 2020 2021 2022 Billable/Specific Code
    Applicable To
    • Contact with and (suspected) exposure to SARS-CoV-2
    Z20.822
    )
  • personal history of COVID-19 (
    ICD-10-CM Diagnosis Code Z86.16

    Personal history of COVID-19

      2016 2017 2018 2019 2020 2021 2022 Billable/Specific Code POA Exempt
    Type 1 Excludes
    • post COVID-19 condition (U09.9)
    Z86.16
    )
  • post COVID-19 condition (
    ICD-10-CM Diagnosis Code U09.9

    Post COVID-19 condition, unspecified

      2022 - New Code Billable/Specific Code
    Code First
    • the specific condition related to COVID-19 if known, such as:
    • chronic respiratory failure (J96.1-)
    • loss of smell (R43.8)
    • loss of taste (R43.8)
    • multisystem inflammatory syndrome (M35.81)
    • pulmonary embolism (I26.-)
    • pulmonary fibrosis (J84.10)
    Note
    • This code enables establishment of a link with COVID-19.
    • This code is not to be used in cases that are still presenting with active COVID-19. However, an exception is made in cases of re-infection with COVID-19, occurring with a condition related to prior COVID-19.
    • Post-acute sequela of COVID-19
    U09.9
    )
Code First
Code First Help
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, 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. In most cases the manifestation codes will have in the code title, "in diseases classified elsewhere." Codes with this title are a component of the etiology/manifestation convention. The code title indicates that it is a manifestation code. "In diseases classified elsewhere" codes are never permitted to be used as first listed or principle diagnosis codes. They must be used in conjunction with an underlying condition code and they must be listed following the underlying condition.
  • , if applicable, COVID-19 (
    ICD-10-CM Diagnosis Code U07.1

    COVID-19

      2016 2017 2018 2019 2020 2021 2022 Billable/Specific Code
    Type 1 Excludes
    • coronavirus infection, unspecified (B34.2)
    • coronavirus as the cause of diseases classified elsewhere (B97.2-)
    • pneumonia due to SARS-associated coronavirus (J12.81)
    Use Additional
    • code to identify pneumonia or other manifestations
    U07.1
    )
Code Also
Code Also Help
A code also note instructs that 2 codes may be required to fully describe a condition but the sequencing of the two codes is discretionary, depending on the severity of the conditions and the reason for the encounter.
  • any associated complications such as:
  • acute hepatic failure (
    ICD-10-CM Diagnosis Code K72.0

    Acute and subacute hepatic failure

      2016 2017 2018 2019 2020 2021 2022 Non-Billable/Non-Specific Code
    Applicable To
    • Acute non-viral hepatitis NOS
    K72.0-
    )
  • acute kidney failure (
    ICD-10-CM Diagnosis Code N17
    • N17 Acute kidney failure
      • N17.0 Acute kidney failure with tubular necrosis
      • N17.1 Acute kidney failure with acute cortical necr...
      • N17.2 Acute kidney failure with medullary necrosis
      • N17.8 Other acute kidney failure
      • N17.9 Acute kidney failure, unspecified
    N17.-
    )
  • acute myocarditis (
    ICD-10-CM Diagnosis Code I40
    • I40 Acute myocarditis
      • I40.0 Infective myocarditis
      • I40.1 Isolated myocarditis
      • I40.8 Other acute myocarditis
      • I40.9 Acute myocarditis, unspecified
    I40.-
    )
  • acute respiratory distress syndrome (
    ICD-10-CM Diagnosis Code J80

    Acute respiratory distress syndrome

      2016 2017 2018 2019 2020 2021 2022 Billable/Specific Code
    Applicable To
    • Acute respiratory distress syndrome in adult or child
    • Adult hyaline membrane disease
    Type 1 Excludes
    • respiratory distress syndrome in newborn (perinatal) (P22.0)
    J80
    )
  • cardiac arrhythmia (
    ICD-10-CM Diagnosis Code I47

    Paroxysmal tachycardia

      2016 2017 2018 2019 2020 2021 2022 Non-Billable/Non-Specific Code
    Code First
    • tachycardia complicating:
    • abortion or ectopic or molar pregnancy (O00-O07, O08.8)
    • obstetric surgery and procedures (O75.4)
    Type 1 Excludes
    • tachycardia NOS (R00.0)
    • sinoauricular tachycardia NOS (R00.0)
    • sinus [sinusal] tachycardia NOS (R00.0)
    I47
    -
    ICD-10-CM Diagnosis Code I49

    Other cardiac arrhythmias

      2016 2017 2018 2019 2020 2021 2022 Non-Billable/Non-Specific Code
    Code First
    • cardiac arrhythmia complicating:
    • abortion or ectopic or molar pregnancy (O00-O07, O08.8)
    • obstetric surgery and procedures (O75.4)
    Type 1 Excludes
    • neonatal dysrhythmia (P29.1-)
    • sinoatrial bradycardia (R00.1)
    • sinus bradycardia (R00.1)
    • vagal bradycardia (R00.1)
    Type 2 Excludes
    I49
    .-)
  • pneumonia due to COVID-19 (
    ICD-10-CM Diagnosis Code J12.82

    Pneumonia due to coronavirus disease 2019

      2016 2017 2018 2019 2020 2021 2022 Billable/Specific Code
    Applicable To
    • Pneumonia due to 2019 novel coronavirus (SARS-CoV-2)
    • Pneumonia due to COVID-19
    Code First
    J12.82
    )
  • severe sepsis (
    ICD-10-CM Diagnosis Code R65.2

    Severe sepsis

      2016 2017 2018 2019 2020 2021 2022 Non-Billable/Non-Specific Code
    Applicable To
    • Infection with associated acute organ dysfunction
    • Sepsis with acute organ dysfunction
    • Sepsis with multiple organ dysfunction
    • Systemic inflammatory response syndrome due to infectious process with acute organ dysfunction
    Code First
    • underlying infection, such as:
    • infection following a procedure (T81.4-)
    • infections following infusion, transfusion and therapeutic injection (T80.2-)
    • puerperal sepsis (O85)
    • sepsis following complete or unspecified spontaneous abortion (O03.87)
    • sepsis following ectopic and molar pregnancy (O08.82)
    • sepsis following incomplete spontaneous abortion (O03.37)
    • sepsis following (induced) termination of pregnancy (O04.87)
    • sepsis NOS (A41.9)
    Use Additional
    • code to identify specific acute organ dysfunction, such as:
    • acute kidney failure (N17.-)
    • acute respiratory failure (J96.0-)
    • critical illness myopathy (G72.81)
    • critical illness polyneuropathy (G62.81)
    • disseminated intravascular coagulopathy [DIC] (D65)
    • encephalopathy (metabolic) (septic) (G93.41)
    • hepatic failure (K72.0-)
    R65.2-
    )
  • viral cardiomyopathy (
    ICD-10-CM Diagnosis Code B33.24

    Viral cardiomyopathy

      2016 2017 2018 2019 2020 2021 2022 Billable/Specific Code
    B33.24
    )
  • viral pericarditis (
    ICD-10-CM Diagnosis Code B33.23

    Viral pericarditis

      2016 2017 2018 2019 2020 2021 2022 Billable/Specific Code
    B33.23
    )
The following code(s) above M35.81 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to M35.81:
  • M00-M99
    2022 ICD-10-CM Range M00-M99

    Diseases of the musculoskeletal system and connective tissue

    Note
    • Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition
    Type 2 Excludes
    • arthropathic psoriasis (L40.5-)
    • certain conditions originating in the perinatal period (P04-P96)
    • certain infectious and parasitic diseases (A00-B99)
    • compartment syndrome (traumatic) (T79.A-)
    • complications of pregnancy, childbirth and the puerperium (O00-O9A)
    • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
    • endocrine, nutritional and metabolic diseases (E00-E88)
    • injury, poisoning and certain other consequences of external causes (S00-T88)
    • neoplasms (C00-D49)
    • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
    Diseases of the musculoskeletal system and connective tissue
  • M30-M36
    2022 ICD-10-CM Range M30-M36

    Systemic connective tissue disorders

    Includes
    • autoimmune disease NOS
    • collagen (vascular) disease NOS
    • systemic autoimmune disease
    • systemic collagen (vascular) disease
    Type 1 Excludes
    • autoimmune disease, single organ or single cell-type -code to relevant condition category
    Systemic connective tissue disorders
  • M35
    ICD-10-CM Diagnosis Code M35

    Other systemic involvement of connective tissue

      2016 2017 2018 2019 2020 2021 2022 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • reactive perforating collagenosis (L87.1)
    Other systemic involvement of connective tissue
ICD-10-CM M35.81 is grouped within Diagnostic Related Group(s) (MS-DRG v39.0):
  • 545 Connective tissue disorders with mcc
  • 546 Connective tissue disorders with cc
  • 547 Connective tissue disorders without cc/mcc
Code History
  • 2021 (effective 10/1/2020): New code
  • 2022 (effective 10/1/2021): No change
Code annotations containing back-references to M35.81:
  • Code First: U09.9
    ICD-10-CM Diagnosis Code U09.9

    Post COVID-19 condition, unspecified

      2022 - New Code Billable/Specific Code
    Code First
    • the specific condition related to COVID-19 if known, such as:
    • chronic respiratory failure (J96.1-)
    • loss of smell (R43.8)
    • loss of taste (R43.8)
    • multisystem inflammatory syndrome (M35.81)
    • pulmonary embolism (I26.-)
    • pulmonary fibrosis (J84.10)
    Note
    • This code enables establishment of a link with COVID-19.
    • This code is not to be used in cases that are still presenting with active COVID-19. However, an exception is made in cases of re-infection with COVID-19, occurring with a condition related to prior COVID-19.
    • Post-acute sequela of COVID-19

Diagnosis Index entries containing back-references to M35.81:
  • MIS-A M35.81
  • MIS-C M35.81
  • Multisystem inflammatory syndrome M35.81 (in adult) (in children)
  • Pediatric inflammatory multisystem syndrome M35.81
  • PIMS M35.81
  • Syndrome - see also Disease
    • multisystem inflammatory M35.81 (in adults) (in children)
    • pediatric inflammatory multisystem M35.81

ICD-10-CM Codes Adjacent To M35.81
M35.0C …… with dental involvement
M35.09 …… with other organ involvement
M35.1 Other overlap syndromes
M35.2 Behçet's disease
M35.3 Polymyalgia rheumatica
M35.4 Diffuse (eosinophilic) fasciitis
M35.5 Multifocal fibrosclerosis
M35.6 Relapsing panniculitis [Weber-Christian]
M35.7 Hypermobility syndrome
M35.8 Other specified systemic involvement of connective tissue
M35.81 Multisystem inflammatory syndrome
M35.89 Other specified systemic involvement of connective tissue
M35.9 Systemic involvement of connective tissue, unspecified
M36 Systemic disorders of connective tissue in diseases classified elsewhere
M36.0 Dermato(poly)myositis in neoplastic disease
M36.1 Arthropathy in neoplastic disease
M36.2 Hemophilic arthropathy
M36.3 Arthropathy in other blood disorders
M36.4 Arthropathy in hypersensitivity reactions classified elsewhere
M36.8 Systemic disorders of connective tissue in other diseases classified elsewhere
M40 Kyphosis and lordosis

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.