Excludes1 pair
C83- vs C88.4-
C83 and C88.4 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 C88.4
high malignant (diffuse large B-cell) lymphoma (C83.3-)
C88.4
Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue [MALT-lymphoma]
Not billable
- Chapter 2
- Neoplasms
- Section
- C81-C96
Use when the record says
- Lymphoma of skin-associated lymphoid tissue [SALT-lymphoma]
- Lymphoma of bronchial-associated lymphoid tissue [BALT-lymphoma]
Indexed under
- Lymphoma › BALT
- Lymphoma › bronchial-associated lymphoid tissue [BALT-lymphoma]
- Lymphoma › extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue [MALT-lymphoma]
- Lymphoma › MALT
- Lymphoma › mucosa-associated lymphoid tissue [MALT-lymphoma]
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