Excludes1 pair

D75.1 vs P61.1

D75.1 and P61.1 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 D75.1
polycythemia neonatorum (P61.1)
D75.1

Secondary polycythemia

Billable
Chapter 3
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
Section
D70-D77
Use when the record says
  • Acquired polycythemia
  • Emotional polycythemia
  • Erythrocytosis NOS
  • Hypoxemic polycythemia
  • Nephrogenous polycythemia
  • Polycythemia due to erythropoietin
  • Polycythemia due to fall in plasma volume
  • Polycythemia due to high altitude
Indexed under
  • Erythrocytosis (megalosplenic) (secondary)
  • Gaisböck's disease (polycythemia hypertonica)
  • Polycythemia (secondary)
  • Polycytosis cryptogenica
  • Pseudopolycythemia
P61.1

Polycythemia neonatorum

Billable
Chapter 16
Certain conditions originating in the perinatal period
Section
P50-P61
Indexed under
  • Plethora › newborn
  • Polycythemia › neonatorum
  • Syndrome › hypertransfusion, newborn
  • Polycythemia › due to › donor twin
  • Polycythemia › due to › maternal-fetal transfusion

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