Published in 2025, Revised in 2026 for NDC-12 Developed by HDA’s EDI 850 Task Force, this electronic data interchange (EDI) transaction set explains how to apply the Accredited Standards Committee (ASC) X12 standards to the Purchase Order (PO) transaction set for use in healthcare distribution. The guideline provides updated Drug Supply Chain Security Act (DSCSA)-compliant recommendations for wholesale distributors on coding EDI 850s and generating subsequent EPCIS transaction data related to standard wholesale distributor replenishment orders, as well as dropship orders. New revisions in this edition include but are not limited to the dispenser PO number in a REF segment immediately following the wholesaler PO in the BEG segment; numerous notes guiding the formation of the DSCSA EPCIS data for the dropship transaction resulting from a dropship PO; addition of a sold-to party to designate either a 340b covered entity or dispenser corporate owner of the product; state license number of the dispenser involved in the transaction; and revised business case examples showcasing the aforementioned new features. The 2026 revisions combine the changes above with Controlled Substance Ordering System EDI PO requirements for finished form-only controlled substances, as well as support for the transition to NDC-12.