M33.21
Billable codePolymyositis with respiratory involvement
The ICD-10 code for polymyositis with respiratory involvement is M33.21.
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
Related codes in this category
- M33.20Polymyositis, organ involvement unspecified
- M33.22Polymyositis with myopathy
- M33.29Polymyositis with other organ involvement
- M33.21Polymyositis with respiratory involvement
ICD-9-CM equivalent
Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.
- 5178Approximate match
- 7104Approximate match
Associated MS-DRGs
M33.21 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.