Excludes1 pair

C56- vs C75-

C56 and C75 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 C75
malignant neoplasm of ovary (C56.-)
C56

Malignant neoplasm of ovary

Not billable
Chapter 2
Neoplasms
Section
C51-C58
Indexed under
  • Carcinoma › granulosa cell
  • Dermoid › with malignant transformation
  • Thecoma › malignant
  • Adenofibroma › endometrioid › malignant
  • Brenner › tumor › malignant
C75

Malignant neoplasm of other endocrine glands and related structures

Not billable
Chapter 2
Neoplasms
Section
C73-C75

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