ICD10BillableValid for clinical use

ICD-10 Code M33.20: Polymyositis, organ involvement unspecified

M33.20 is a billable ICD-10 diagnosis code used to classify Polymyositis, organ involvement unspecified in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the musculoskeletal system and connective tissue (M00-M99).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the musculoskeletal system and connective tissue (M00-M99).

When is it used?

  • May be used when a clinician documents polymyositis, organ involvement unspecified in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
13Diseases of the musculoskeletal system and connective tissue (M00-M99)
block
M30-M36Systemic connective tissue disorders
category
M33Dermatopolymyositis
category
M33.2Polymyositis
currentM33.2

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

Orthopedic SpecialistRheumatologist

Coding guidelines

Common synonyms

Polymyositis, organ involvement unspecifiedPolymyositis, organ involvement

Frequently asked questions

Code details

CodeM33.20
SystemICD10
Display namePolymyositis, organ involvement unspecified
ChapterDiseases of the musculoskeletal system and connective tissue (M00-M99)
BlockSystemic connective tissue disorders

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Polymyositis(acute) (chronic) (hemorrhagic)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code M33.20 for Polymyositis, organ involvement unspecified | HealthAssure