EDI 850/855/856 with McKesson, Cardinal Health, Medline — what do we build vs what does the vendor ship?

Each distributor handles EDI slightly differently. What we build per merchant:

• Magento side — order observer that emits EDI 850 (PO) on order place, ingests EDI 855 (PO acknowledgment) to update cart-line backorder ETA, ingests EDI 856 (ASN advance ship notice) to update fulfillment status + tracking, ingests EDI 810 (invoice) for AP reconciliation. Plus exception monitoring: if a 855 doesn’t arrive within SLA, alert + retry.
• Translator layer — we use TrueCommerce, SPS Commerce, or DiCentral as the X12 translator between Magento JSON and X12 EDI. Cost: ~$300–$1,500/mo depending on transaction volume. For very high-volume merchants (10k+ orders/mo) we roll a custom AS2 + X12 stack and skip the SaaS translator (saves ~$15k/yr at scale).
• Distributor side — McKesson has their SupplyManager EDI program (well-documented, friendly). Cardinal has Cardinal Health Direct EDI (good docs, longer onboarding). Medline has Medline EDI (decent docs, requires their compliance review).

Typical timeline: 4–8 weeks per distributor including their sandbox certification. The first distributor takes longest because we’re building the translator pipeline; subsequent distributors take 2–3 weeks each. Henry Schein Medical and AvaCare Medical follow the same pattern.