ICD-10 Code A37.9 – Whooping cough, unspecified species (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A37.9 – Whooping cough, unspecified species
What it is
A37.9 identifies whooping cough when the species is not specified in the record. Use it for a Bordetella pertussis infection documented as pertussis or whooping cough without further detail.
Clinical signs
Clinical features vary; refer to documentation. Typical pertussis includes paroxysmal coughing spells, inspiratory “whoop,” posttussive vomiting, and prolonged cough illness.
When to use this code
Use A37.9 when the provider documents whooping cough or pertussis but does not identify the species or organism. It also fits when the note confirms the diagnosis yet gives no further classification. Check documentation if another Bordetella species or a more specific code is stated.
Do not use for
Do not use this code for cough alone, suspected pertussis without confirmation, or a more specific whooping cough code when the organism or species is documented. Check documentation.
Coding tip
Code the documented diagnosis exactly as stated and query for species details if they would change code assignment.