Excludes1 pair

D40.8 vs D48.5

D40.8 and D48.5 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 D48.5
neoplasm of uncertain behavior of skin of genital organs (D39.8, D40.8)
D40.8

Neoplasm of uncertain behavior of other specified male genital organs

BillableUnspecified
Chapter 2
Neoplasms
Section
D37-D48
Use when the record says
  • Neoplasm of uncertain behavior of skin of male genital organs
D48.5

Neoplasm of uncertain behavior of skin

Billable
Chapter 2
Neoplasms
Section
D37-D48
Use when the record says
  • Neoplasm of uncertain behavior of anal margin
  • Neoplasm of uncertain behavior of anal skin
  • Neoplasm of uncertain behavior of perianal skin
  • Neoplasm of uncertain behavior of skin of breast
Indexed under
  • Nevus › bathing trunk
  • Tumor › basal cell
  • Nevus › pigmented › giant

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