ICD-10 Code E73 – Lactose intolerance (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E73 – Lactose intolerance
What it is
E73 identifies lactose intolerance, a condition in which the body cannot properly digest lactose, the sugar in milk and dairy products. It usually reflects reduced lactase enzyme activity.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include bloating, abdominal pain, gas, and diarrhea after consuming lactose-containing foods or drinks.
When to use this code
Use E73 when the provider documents lactose intolerance as the diagnosed cause of dairy-related gastrointestinal symptoms. It may also apply when testing or clinical assessment supports lactose malabsorption with symptoms, if documented. Check documentation for the exact type, if specified.
Do not use for
Do not use this code for nonspecific abdominal pain, diarrhea, or milk allergy without documentation of lactose intolerance. If the record is unclear, check documentation.
Coding tip
Assign E73 only when the clinician clearly links symptoms to lactose intolerance or documents the diagnosis directly.