Excludes1 pair
D58.2 vs D74.0
D58.2 and D74.0 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 D58.2
Hb-M disease (D74.0)
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
D74.0
Congenital methemoglobinemia
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
- Congenital NADH-methemoglobin reductase deficiency
- Hemoglobin-M [Hb-M] disease
- Methemoglobinemia, hereditary
Indexed under
- Deficiency, deficient › NADH diaphorase or reductase (congenital)
- Deficiency, deficient › NADH-methemoglobin reductase (congenital)
- Disease, diseased › diaphorase deficiency
- Methemoglobinemia › congenital
- Methemoglobinemia › enzymatic (congenital)
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