ICDcodes.org
FY2027

A91 vs A98

A91 and A98 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.

The official note, declared on A98
dengue hemorrhagic fever (A91)
A91

Dengue hemorrhagic fever

Billable
Chapter 1
Certain infectious and parasitic diseases
Section
A90-A99
Indexed under
  • Bangkok hemorrhagic fever
  • Singapore hemorrhagic fever
  • Southeast Asian hemorrhagic fever
  • Thailand hemorrhagic fever
  • Dengue › hemorrhagic (classical) (fever)
A98

Other viral hemorrhagic fevers, not elsewhere classified

Not billable
Chapter 1
Certain infectious and parasitic diseases
Section
A90-A99

Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027