## **What is the HCPCS code J9358 for?**
Please note that if you're looking for a J9358 CPT code description, we'd like you to know that J9358 should not be mistaken for a CPT code. It's an HCPCS code that refers to an injection medication, specifically fam-trastuzumab deruxtecan-nxki. According to the National Comprehensive Cancer Network, this medicine is a type of antibody drug conjugate, a chemotherapy drug that's meant to be given to cancer patients dealing with certain types of cancer, such as metastatic breast cancer (secondary malignant neoplasm of the breasts).
This type of medicine is meant to deliver cell-specific chemotherapy that destroys cancer cells, especially those that have made their way to the upper limb lymph nodes/intra-abdominal lymph nodes.
If your (adult) patient is dealing with a currently unspecified malignant neoplasm, don't use this. Once your patient is confirmed to be dealing with HER2-positive breast cancer or any HER2-expressing tumors (like gastric cancer), then this is one of the medicines you can use. This medicine is geared to shrink tumors and prevent them from growing.
Please ensure that you follow NCCN clinical practice guidelines when administering this injection medicine.
## **Documentation requirements for J9358**
As with any injected medication, J9358 requires proper documentation before being filed for billing and claims. Make sure to document the following:
- The full name of the personnel who administered the injection and their credentials
- The name and address of the facility where the injection was administered
- The full name of the patient
- The date and time of the drug administration by injection
- Patient records showing they have been diagnosed with an HER2-expressing tumor/cancer
- All test results that were conducted for the diagnosis (including the biopsies)
- A record of all adverse events, supportive care, and patient responses
- Blood tests (complete blood counts)
- Imaging test results showing the location and sizes of the malignant tumors
- Medical necessity for the use of the medicine
- Exact dosage of fam-trastuzumab deruxtecan-nxki
## **Billing requirements for J9358**
Besides the documentation requirements above, please note that you need to combine this HCPCS code with the CPT code 96365 for intravenous infusion, for therapy, prophylaxis, or diagnosis.
You must also note the following:
- The documentation must reflect the dosage given throughout the treatment.
- Use either of the two modifiers: JW if there's unused medication in a vial (wastage), or JZ if there's no unused medication.
Make sure you also use the proper diagnosis code related to the specific type of cancer the patient has, especially if the cancer is in the breast. For breast cancers, there are codes for unspecified female breast and unspecified male breast, but it's best to settle for ICD-10-CM codes that are more specific, like for the left female breast, right female breast, and right male breast.
Always follow proper billing and coding guidelines for HCPCS, CPT, and ICD codes to avoid claim rejections.
## **Other similar HCPCS codes**
- J9355 - Injection, trastuzumab, excludes biosimilar, 10 mg
- J9316 - Injection, pertuzumab, trastuzumab, and hyaluronidase-zzxf, per 10 mg
- J9313 - Injection, moxetumomab pasudotox-tdfk, 0.01 mg
- J9318 - Injection, romidepsin, nonlyophilized, 0.1 mg
Frequently asked questions
