ICD-10 Code B46.4 – Disseminated Mucormycosis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B46.4 – Disseminated mucormycosis
What it is
Disseminated mucormycosis is a severe invasive fungal infection caused by Mucorales species that spreads beyond the original site of infection. Use this code when documentation states the infection is disseminated or widely spread.
Clinical signs
Clinical features vary; refer to documentation. Patients may have signs of infection in multiple organs, with rapidly progressive illness in an immunocompromised or critically ill person.
When to use this code
Use B46.4 when the provider documents disseminated mucormycosis, systemic mucormycosis, or fungal infection involving more than one body site. Code it when the record clearly supports spread beyond a localized sinus, lung, skin, or other single focus. Check documentation if the extent is unclear.
Do not use for
Do not use this code for localized mucormycosis limited to one site, such as rhinocerebral, pulmonary, cutaneous, or gastrointestinal disease. If dissemination is not documented, choose the more specific site code or check documentation.
Coding tip
Confirm that the record explicitly states dissemination; site-specific mucormycosis codes may be more accurate when spread is not documented.