Excludes1 pair

C83.0- vs C88.0-

C83.0 and C88.0 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 C88.0
small cell B-cell lymphoma (C83.0)
C83.0

Small cell B-cell lymphoma

Not billable
Chapter 2
Neoplasms
Section
C81-C96
Use when the record says
  • Lymphoplasmacytic lymphoma
  • Nodal marginal zone lymphoma
  • Non-leukemic variant of B-CLL
  • Splenic marginal zone lymphoma
Indexed under
  • Immunocytoma
  • Lymphoma › lymphoplasmacytic
  • Lymphoma › nodal marginal zone
  • Lymphoma › non-leukemic variant of B-CLL
  • Lymphoma › small cell B-cell
C88.0

Waldenstrom macroglobulinemia

Not billable
Chapter 2
Neoplasms
Section
C81-C96
Use when the record says
  • Lymphoplasmacytic lymphoma with IgM-production
  • Macroglobulinemia (idiopathic) (primary)
Indexed under
  • Macroglobulinemia (idiopathic) (primary)
  • Macroglobulinemia › Waldenström
  • Waldenström › syndrome or macroglobulinemia
  • Disorder › glomerular › Waldenström macroglobulinemia
  • Glomerulonephritis › in › Waldenström macroglobulinemia

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