Oncology & Hematology Coding Alert

Question: When are we supposed to use modifier KX?


Idaho Subscriber

Answer: Using KX (Specific required documentation on file) tells the payer that you actually have required documentation on file. Rule: Only use this code when a payer policy specifically tells you to, as directed by Transmittal B-02-026, available at www.cms.hhs.gov/manuals/pm_trans/B02026.pdf.

In other words, don't report modifier KX just because you know you need to have certain information on file to report a specific code (such as only coding a chemo drug if the physician or his auxiliary personnel administered the medication). Instead: Watch payer policies for specific references to KX and append the modifier only in those cases when a payer requires it.

Example: Cigna Medicare tells Idaho providers to append KX to the HCPCS code for chemotherapy drugs used off-label to treat cancer. The provider must have documentation in the medical record to support this off-label therapy choice, including any supporting evidence.