ICD-10 Code J84.02 – Pulmonary alveolar microlithiasis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J84.02 – Pulmonary alveolar microlithiasis
What it is
J84.02 identifies pulmonary alveolar microlithiasis, a rare lung disorder in which tiny calcium phosphate deposits accumulate in the alveoli. Use it when the diagnosis is documented specifically and you need the exact condition coded.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include diffuse lung changes on imaging, progressive shortness of breath, and cough, but the diagnosis is usually confirmed by characteristic radiologic or pathologic evidence.
When to use this code
Use J84.02 when the provider documents pulmonary alveolar microlithiasis as the confirmed diagnosis. This code is appropriate for outpatient encounters, problem lists, and follow-up visits when the condition remains active or is being evaluated.
If the record only mentions abnormal chest imaging or another interstitial lung disease without naming this disorder, do not assume J84.02. Check documentation and code the most specific documented diagnosis.
Do not use for
Do not use this code for nonspecific lung calcification, other interstitial lung diseases, or suspected disease without confirmation. Check documentation if the note does not clearly identify pulmonary alveolar microlithiasis.
Coding tip
Look for explicit wording such as “pulmonary alveolar microlithiasis” in the assessment or confirmed imaging report before assigning J84.02.