Basics of C9399 CPT/HCPCS  code

HCPCS code C9399 should be reported for new drugs, biologicals and therapeutic radiopharmaceuticals that are approved by the Food and Drug Administration (FDA) but not approved for pass-through status and a HCPCS C-code hasn’t been assigned. Please note: Diagnostic radiopharmaceuticals and contrast agents should be reported with the appropriate HCPCS A-codes (e.g., A4641 Radiopharmaceutical, diagnostic, not otherwise classified)

If commercially available products are being mixed together to facilitate their concurrent administration, the quantity of each product used should be reported with the appropriate HCPCS code. Alternatively, if compounding drugs that are not a mixture of commercially available products, but are a different product without an applicable HCPCS code, then the appropriate unlisted drug code (J9999 or J3490) should be reported. In these situations, it is not appropriate to bill HCPCS code C9399.

The Medicare Claims Processing Manual, Pub. 100-04, Chapter 17, Sections 90.2 and 90.3, provides further clarification regarding HCPCS code C9399, Unclassified drugs or biologicals, for outpatient hospital reporting:

“Hospitals are to report HCPCS code C9399, solely for new outpatient drugs or biologicals that are approved by the FDA on or after January 1, 2004 and that are furnished as part of covered outpatient department services for which a product-specific HCPCS code has not been assigned.”

ASCs are strongly encouraged to report charges for all separately payable drugs and biologicals, using the correct HCPCS codes for the items used.

We remind ASCs that under the ASC payment system if two or more drugs or biologicals are mixed together to facilitate administration, the correct HCPCS codes should be reported separately for each product used in the care of the patient. The mixing together of two or more products does not constitute a “new” drug as regulated by the Food and Drug Administration (FDA) under the New Drug Application (NDA) process. In these situations, ASCs are reminded that it is not appropriate to bill HCPCS code C9399. 

Unlisted description of J3490, J3590,  J9999 & C9399 HCPCS code for drugs and biologicals

A biologic is defined as a medicinal preparation made from living organisms and/or their products, including serums, vaccines, antigens, antitoxins, etc.

A compound drug is a pharmacy prepared medication containing one or more active ingredients. Compound drugs may be prepared for administration in one of several ways: oral use, implanted, topical (cream or gel), as an injectable, in a nebulizer, intravenously, or an intrathecal pump

J3490 – Unclassified drugs

J3590 – Unclassified biologics

HCPCS codes J3490, Unclassified drugs, and J3590, Unclassified biologics, should be reported if a drug or biological does not have an established HCPCS code assigned.

J9999 – Not otherwise classified, antineoplastic drugs

HCPCS code J7999, Compounded drug, not otherwise classified, has been effective since January 1, 2016 and is reported for compounded drugs

Unlisted codes are commonly used when the:

1. Drug/biological does not have a specific HCPCS code
2. Drug/biological is administered by a route other than stated in the code
3. Amount of drug or biological is less than the amount, or of a different concentration, than specified in the HCPCS descriptor

To report new drugs and biologicals, approved by the Food and Drug Administration, for which there are no specific HCPCS codes assigned, use HCPCS code C9399, “unclassified drugs or biologicals”. This code applies only to hospital outpatient departments who bill under the Outpatient Prospective Payment System (OPPS)

C9399 Unclassified drugs or biologicals

Billing for C9399 CPT/HCPCS code

When HCPCS code C9399 is reported, remarks must include:

Name of drug

Dosage (mg, mL, etc.)

Route of administration (IV, IM, SC, PO, etc.)