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Reimbursement of Biosimilars Without Q Codes


The future of drugs is biosimilars, as controlling costs has long been a focus of the Centers for Medicare & Medicaid Services (CMS) and private payers. While generic drugs are identical to their branded counterpart, biosimilars are a biological product that is highly similar to its reference product, notwithstanding the minor differences in its clinically inactive components. Given the complexity of how biosimilars are grown (complex living systems vs. chemical synthetization in generics), it is unlikely for biosimilars to be exact replicas of the original.
As biosimilars first came to the market, CMS developed Q codes affiliated with the product name and corresponding modifier to denote different manufacturers. After April 1, 2018, CMS assigned individual Q codes unique to the product representing the drug name, dosage and units, with no required modifier denoting the manufacturer.

As a new biosimilar comes to market and until a Q code is assigned, CMS allows the use of a “not otherwise classified” code or unassigned codes in the interim. Dates of service before April 1, 2018, used the HCPCS code Q5102. To be reimbursed by CMS, the NDC must be in CMS’ Box 19, even if it is automatically entered on forms.

For questions regarding coding and reimbursements, send an email to

This information was taken from a webinar Best Practice Billing NOC and Unspecified Codes in November 2018.