ICD-10 Code A37.01 – Whooping cough due to Bordetella pertussis with pneumonia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A37.01 – Whooping cough due to Bordetella pertussis with pneumonia
What it is
A37.01 identifies pertussis caused by Bordetella pertussis when pneumonia is also present. Use it for confirmed whooping cough with a documented pneumonia complication.
Clinical signs
Typical findings include paroxysmal coughing spells, inspiratory whoop, posttussive vomiting, or apnea in infants. Clinical features vary; refer to documentation for evidence of pneumonia.
When to use this code
Use this code when the record clearly states Bordetella pertussis infection and pneumonia together. It fits cases where the clinician documents pertussis pneumonia, or confirms pneumonia as a complication of whooping cough.
Do not use it if pertussis is suspected but not confirmed, or if pneumonia is documented without a pertussis diagnosis. Check documentation for the exact organism and complication.
Do not use for
Do not use for nonpertussis cough illnesses, unspecified pneumonia, or pertussis without pneumonia. If the chart does not confirm Bordetella pertussis, code the documented condition instead.
Coding tip
Look for explicit linkage between pertussis and pneumonia in the provider note before assigning A37.01.