October 1 update. Our PDGM and ICD-10 tools now use the FY2027 code set: 190 codes added, 30 deleted, and no existing code changed clinical group.

See what changed

ICD-10 · PDGM grouping

A37 Whooping cough

All 8 codes in the A37 family, with the PDGM clinical group, comorbidity subgroup and primary-position rule CMS assigns, read from the CMS grouper crosswalk v07.2.26 and the CDC FY2027 code file.

ICD-10-CM FY2027 · CMS grouper v07.2.26

Codes in family

8

Can lead a claim

8

Cannot lead a claim

0

What CMS assigns to A37

All 8 codes group to MMTA - Infectious Disease, Neoplasms, and Blood-Forming Diseases. 4 of the 8 count toward the Whooping Cough and Pneumonia comorbidity subgroup; 4 are assigned none. Every code can lead a claim.

  • Whooping Cough and Pneumonia: counts toward the high comorbidity tier only in an interaction pair.

Every code in A37

Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.

CodeDescriptionPrimary positionClinical groupComorbidity subgroup
A37.0 Whooping cough due to Bordetella pertussis
A37.00Whooping cough due to Bordetella pertussis without pneumoniaCan lead a claimKNone
A37.01Whooping cough due to Bordetella pertussis with pneumoniaCan lead a claimKWhooping Cough and Pneumonia
A37.1 Whooping cough due to Bordetella parapertussis
A37.10Whooping cough due to Bordetella parapertussis without pneumoniaCMS: Whooping cough due to Bordetella parapertussis w/o pneumoniaCan lead a claimKNone
A37.11Whooping cough due to Bordetella parapertussis with pneumoniaCMS: Whooping cough due to Bordetella parapertussis w pneumoniaCan lead a claimKWhooping Cough and Pneumonia
A37.8 Whooping cough due to other Bordetella species
A37.80Whooping cough due to other Bordetella species without pneumoniaCMS: Whooping cough due to other Bordetella species w/o pneumoniaCan lead a claimKNone
A37.81Whooping cough due to other Bordetella species with pneumoniaCMS: Whooping cough due to oth Bordetella species with pneumoniaCan lead a claimKWhooping Cough and Pneumonia
A37.9 Whooping cough, unspecified species
A37.90Whooping cough, unspecified species without pneumoniaCan lead a claimKNone
A37.91Whooping cough, unspecified species with pneumoniaCan lead a claimKWhooping Cough and Pneumonia

Sources: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01, for the clinical group, comorbidity subgroup, code-first conventions and primary-position flags; CDC NCHS ICD-10-CM FY2027 code descriptions for the family title and code wording. This is the crosswalk Medicare runs a claim through. Grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list.

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