2026 Unspecified Behavior ICD-10-CM Codes ICD-10-CM
The FY 2026 dataset contains 12 unspecified behavior codes across 1 code blocks. Unspecified behavior codes document tumors whose behavior is not stated in the medical record, the Unspecified Behavior column of the Table of Neoplasms. Each code below lists the anatomical sites that map to it.
Coding Guidance
Review the documentation before defaulting to unspecified behavior: improper use can delay claims and impact reimbursement. A pathology report usually supports a more specific behavior column.
All Unspecified Behavior Codes 12 codes · searchable by anatomical site
Neoplasms of unspecified behavior D49 · 12 codes
- D49.0 Neoplasm of unspecified behavior of digestive system
- D49.1 Neoplasm of unspecified behavior of respiratory system
- D49.2 Neoplasm of unspecified behavior of bone, soft tissue, and skin
- D49.3 Neoplasm of unspecified behavior of breast
- D49.4 Neoplasm of unspecified behavior of bladder
- D49.51 Neoplasm of unspecified behavior of kidneyNon-billable header
- D49.59 Neoplasm of unspecified behavior of other genitourinary organ
- D49.6 Neoplasm of unspecified behavior of brain
- D49.7 Neoplasm of unspecified behavior of endocrine glands and other parts of nervous system
- D49.81 Neoplasm of unspecified behavior of retina and choroid
- D49.89 Neoplasm of unspecified behavior of other specified sites
- D49.9 Neoplasm of unspecified behavior of unspecified site
The info icon lists every anatomical site from the table that maps to the code. The filter above searches those anatomical sites too.
Questions About This Page
How do I find the right code for a specific site?
Type the anatomical site into the filter above. Every code on this page carries the site entries that map to it in the Table of Neoplasms. For all six behavior columns side by side, use the Table of Neoplasms.
How is neoplasm behavior determined?
The pathology or clinical documentation names the behavior. When the description of the neoplasm states the behavior, that description overrides the Index guidance, and the matching column of the Table of Neoplasms supplies the code.
How many unspecified behavior codes are there?
The FY 2026 dataset contains 12 unspecified behavior codes across 1 code blocks, 11 of them billable.
Related References
Source: official CMS FY 2026 ICD-10-CM release, effective October 1, 2025 through September 30, 2026.
