Excludes1 pair

I89- vs Q82.0

I89 and Q82.0 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 I89
hereditary lymphedema (Q82.0)
I89

Other noninfective disorders of lymphatic vessels and lymph nodes

Not billable
Chapter 9
Diseases of the circulatory system
Section
I80-I89
Q82.0

Hereditary lymphedema

Billable
Chapter 17
Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
Section
Q80-Q89
Indexed under
  • Meige-Milroy disease (chronic hereditary edema)
  • Meige's syndrome
  • Milroy's disease (chronic hereditary edema)
  • Nonne-Milroy syndrome
  • Pseudoelephantiasis neuroarthritica

These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.

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