ICD-10 Code D49.89 – Neoplasm of unspecified behavior of other specified sites (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D49.89 – Neoplasm of unspecified behavior of other specified sites
What it is
This code describes a growth in a specified site that is not clearly identified as benign or malignant. Use it when the record says the lesion has uncertain behavior and the site is “other specified.”
Clinical signs
Clinical features vary; refer to documentation. You may see a mass, lesion, or abnormal tissue found on exam, imaging, or pathology, but the behavior is not yet established.
When to use this code
Use this code when the provider documents a neoplasm with uncertain behavior at a site that does not have a more specific code. It is appropriate when pathology, imaging, or the assessment states “unspecified behavior” or similar wording.
Code from the documented site and behavior, and do not assume malignancy or benign status. If the exact site is not stated clearly, check documentation before assigning D49.89.
Do not use for
Do not use this code for benign neoplasms, malignant neoplasms, or neoplasms of clearly named sites that have a more specific code. Check documentation if the behavior is stated as uncertain but the site is different.
Coding tip
Match both the site and the documented behavior exactly; if either is unclear, query the provider.