D48.6 (Neoplasm of uncertain behavior of breast) compared with D49.3 (Neoplasm of unspecified behavior of breast), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Not coded here — these two are mutually exclusive.
“neoplasms of unspecified behavior (D49.-)”
An Excludes1 note means the two conditions cannot occur together, so the pair should not be reported for the same encounter. The sole exception is when the conditions are documented as unrelated to each other.
Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a
Distinct conditions — both may be reported.
“neoplasms of uncertain behavior (D37-D44, D48)”
An Excludes2 note means the excluded condition is not part of the code above it, but a patient can have both. Report both when both are documented.
Source: CMS ICD-10-CM tabular instructional notes
No — do not report together. D48.6 carries an Excludes1 note covering D49.3: “neoplasms of unspecified behavior (D49.-)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Yes, when both are documented. D49.3 carries an Excludes2 note covering D48.6: “neoplasms of uncertain behavior (D37-D44, D48)”
Excludes2 marks distinct conditions — both may be reported when both are documented.
| D48.6Neoplasm of uncertain behavior of breast | D49.3Neoplasm of unspecified behavior of breast | |
|---|---|---|
| Billing status | Non-billable header | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Neoplasm of uncertain behavior of breast is a non-billable ICD-10-CM category code (D48.6). | Neoplasm of unspecified behavior of breast is a billable ICD-10-CM diagnosis code (D49.3). |
| Includes | Neoplasm of uncertain behavior of connective tissue of breast Cystosarcoma phyllodes | 'growth' NOS neoplasm NOS new growth NOS tumor NOS |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources