ICD-10 Code K31.83 – Achlorhydria (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K31.83 – Achlorhydria
What it is
Achlorhydria means the stomach produces little or no hydrochloric acid. Use this code when documentation states absent gastric acid secretion or a diagnosis of achlorhydria.
Clinical signs
Clinical features vary; refer to documentation. Patients may have findings related to low gastric acidity, but the diagnosis is usually based on clinical assessment or testing rather than symptoms alone.
When to use this code
Use K31.83 when the provider clearly documents achlorhydria as a diagnosis. It is appropriate when the record identifies absent or markedly reduced gastric acid production. If the note only mentions gastritis, dyspepsia, or another stomach complaint, check documentation before assigning this code.
Do not use for
Do not use this code for general indigestion, reflux, or nonspecific abdominal pain without documented achlorhydria. Do not assign it when the chart only suggests low acid levels but does not confirm the condition.
Coding tip
Code only when the provider documents achlorhydria explicitly; otherwise, query or check documentation.