The agency stated that the JZ modifier (zero drug amount discarded/not administered to any patient) “will be required for all drugs separately payable under Part B that are designated as a single-dose container on the FDA-approved label or package insert for which there are no discarded amounts” in the 2023 Medicare Physician Fee Schedule (MPFS), published Nov. 18, 2022. All suppliers and providers who purchase and bill Medicare Part B separately payment medications (single dose container/package) are subject to the JZ modifier. The modifier is eligible for billing as of January 1, and CMS has given providers until July 1 to adopt it.