Excludes1 pair

D58.2 vs D74-

D58.2 and D74 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 D58.2
methemoglobinemia (D74.-)
D58.2

Other hemoglobinopathies

Billable
Chapter 3
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
Section
D55-D59
Use when the record says
  • Abnormal hemoglobin NOS
  • Congenital Heinz body anemia
  • Hb-C disease
  • Hb-D disease
  • Hb-E disease
  • Hemoglobinopathy NOS
  • Unstable hemoglobin hemolytic disease
Indexed under
  • Heinz body anemia, congenital
  • Hemoglobinopathy (mixed)
  • Abnormal, abnormality, abnormalities › hemoglobin (disease)
  • Anemia › Heinz body, congenital
  • Hemoglobin › Constant Spring
D74

Methemoglobinemia

Not billable
Chapter 3
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
Section
D70-D77

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