A91

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.

ICD-9-CM equivalent

Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.

• 0654Approximate match

Associated MS-DRGs

A91 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.

• DRG 849Radiotherapy
• DRG 865Viral Illness with MCC
• DRG 866Viral Illness without MCC