Excludes1 pair
E21- vs E34.2
E21 and E34.2 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 E21
ectopic hyperparathyroidism (E34.2)
E21
Hyperparathyroidism and other disorders of parathyroid gland
Not billable
- Chapter 4
- Endocrine, nutritional and metabolic diseases
- Section
- E20-E35
E34.2
Ectopic hormone secretion, not elsewhere classified
BillableUnspecified
- Chapter 4
- Endocrine, nutritional and metabolic diseases
- Section
- E20-E35
Indexed under
- Ectopic, ectopia › hormone secretion NEC
- Secretion › hormone › ectopic NEC
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