ICD-10 codes D48.5 and D49.2 are often used incorrectly and are often confused. However, carriers typically accept either of them for procedures like biopsies or shave removals that require medical necessity. Make sure you are using them correctly, and assigning them at the appropriate time.
Here are two examples of correct usage.
The provider performs a small punch biopsy and sends it off to pathology. The biller submits the claim with a working diagnosis of Neoplasm, unspecified behavior.
D49.2 Neoplasm of unspecified behavior of bone, soft tissue, and skin
In this case, based on all known clinical knowledge, the provider is unable to specify the type of lesion Therefore, it’s unspecified, not uncertain. Although CMS and many commercial carriers have stated that it's inappropriate (in most cases) to use "unspecified" codes when more appropriate choices are available, this is one of the exceptions. Based on all clinical knowledge at the time of the encounter, the provider is unable to specify the type of lesion. Therefore, D49.2 is acceptable here!
The provider excises a suspicious lesion and sends it off to pathology. Suspecting it might be malignant, and knowing that benign vs. malignant affects the CPT code billed, the practice holds the claim and waits for pathology. However, the dermatolopathologist is unable to determine the nature of the type of lesion. The returned diagnosis from path is “Neoplasm, uncertain behavior.”
D48.5 Neoplasm of uncertain behavior of skin
In this case, neither the dermatologist or dermatopathologist can determine the type or nature of the lesion. They aren’t certain what it is. In this case the use of an uncertain code is acceptable.
Noridian has, for example, specified in their Local Coverage Determination Policies the following
"Regarding other Malignancy:
“When a diagnosis of malignancy has not yet been established at the time the biopsy procedure was performed, the correct diagnosis code to list on the claim would most likely be D49.2, (Neoplasm of unspecified behavior, bone soft tissue, and skin).”