ICD-10-CM 2027
ICD-10 code for whooping cough
Whooping cough, unspecified species without pneumonia
From the official ICD-10-CM alphabetic index entry “Whooping cough”. Page updated September 29, 2026.
About coding whooping cough
The ICD-10-CM code for whooping cough is A37.90 (Whooping cough, unspecified species without pneumonia). The official index lists 13 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on A37.90.
Within A37.9, choose A37.90 (without pneumonia) only when documentation doesn't support a more specific option: with pneumonia (A37.91).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 202 (Bronchitis and Asthma with CC/MCC, relative weight 0.9474) and DRG 203 (Bronchitis and Asthma without CC/MCC, relative weight 0.6512), in MDC 04 (Diseases and Disorders of the Respiratory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific whooping cough codes (official index)
- with pneumonia A37.91 — Whooping cough, unspecified species with pneumonia
- due to Bordetella
- bronchiseptica A37.81 — Whooping cough due to other Bordetella species with pneumonia
- parapertussis A37.11 — Whooping cough due to Bordetella parapertussis with pneumonia
- pertussis A37.01 — Whooping cough due to Bordetella pertussis with pneumonia
- specified organism NEC A37.81 — Whooping cough due to other Bordetella species with pneumonia
- due to
- Bordetella
- bronchiseptica A37.80 — Whooping cough due to other Bordetella species without pneumonia
- with pneumonia A37.81 — Whooping cough due to other Bordetella species with pneumonia
- parapertussis A37.10 — Whooping cough due to Bordetella parapertussis without pneumonia
- with pneumonia A37.11 — Whooping cough due to Bordetella parapertussis with pneumonia
- pertussis A37.00 — Whooping cough due to Bordetella pertussis without pneumonia
- with pneumonia A37.01 — Whooping cough due to Bordetella pertussis with pneumonia
- specified NEC A37.80 — Whooping cough due to other Bordetella species without pneumonia
- with pneumonia A37.81 — Whooping cough due to other Bordetella species with pneumonia
Common questions about whooping cough ICD-10 codes
What is the ICD-10 code for whooping cough?
- A37.90 — Whooping cough, unspecified species without pneumonia. More specific codes apply when the documentation supports them: A37.91, A37.81, A37.11, A37.01 and others below.
Is A37.90 billable?
- Yes. A37.90 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A37.90 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A37.90 as a principal diagnosis.
Is A37.90 a CC or MCC?
- A37.90 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.