ICD-10 Code E83.31 – Familial Hypophosphatemia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E83.31 – Familial hypophosphatemia
What it is
Familial hypophosphatemia is an inherited disorder of phosphate handling that leads to chronically low phosphate availability for normal bone mineralization. You use this code when the record identifies the familial form specifically.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include rickets or osteomalacia, bone pain, deformities, delayed growth, and recurrent fractures related to phosphate wasting.
When to use this code
Use E83.31 when the clinician documents familial hypophosphatemia, hereditary phosphate wasting, or an inherited hypophosphatemic disorder. It may appear in pediatric or adult records when the diagnosis is established and clearly linked to the familial condition.
If the note only says hypophosphatemia without a hereditary cause, check documentation before coding this category. Confirm that the diagnosis is not a temporary electrolyte abnormality or another metabolic bone disorder.
Do not use for
Do not use this code for acquired or unspecified hypophosphatemia. If the documentation does not identify a familial or inherited form, code the condition that is actually stated.
Coding tip
Look for wording such as “familial,” “hereditary,” or “genetic” in the assessment before assigning E83.31.