Excludes1 pair

N13.4 vs N28.8-

N13.4 and N28.8 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.

The official note, declared on N28.8
hydroureter (N13.4)
N13.4

Hydroureter

Billable
Chapter 14
Diseases of the genitourinary system
Section
N10-N16
Indexed under
  • Hydroureter
  • Dilatation › ureter › due to obstruction
N28.8

Other specified disorders of kidney and ureter

Not billable
Chapter 14
Diseases of the genitourinary system
Section
N25-N29

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