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General information only, not medical or purchasing advice. This page describes how published sources treat product substitution in medical and laboratory supply buying. It does not tell any facility what to accept.
Short answer
Product substitution is the supply of a different item from the one specified on an order or contract. In medical and laboratory purchasing, the buyer’s own supply chain office decides whether to accept it: one health authority’s vendor guidelines state that no product substitutions are accepted without prior authorization by the appropriate Supply Chain representative. A separate question, owned by the manufacturer, is whether a change to the same device needs a new FDA premarket notification.
Definition and scope
In this guide, product substitution means an item other than the one ordered or contracted for arrives, or is offered, in its place. Three situations share the word, and they have different owners:
- A substitute the buyer chooses. A buyer replaces an item, for example after a discontinuation. The CASRAI entry on backorder versus discontinued vendor status codes covers that case: confirm the replacement meets the same specification and ask the vendor for a cross-reference SKU.
- A substitute the vendor proposes. The vendor offers a different item. Under the vendor guidelines of the Provincial Health Services Authority (PHSA) in British Columbia, this needs prior authorization before it is accepted.
- A change inside the same product. The manufacturer changes a material or a material supplier. That is a manufacturer decision made under its quality system, not a buyer decision.
Pharmacy generic-drug substitution is a different subject with its own rules and is outside this page.
How does product substitution work in a medical supply purchase?
It depends on whose rules apply. One published policy, the PHSA vendor guidelines for products, sets these conditions for its own supplier relationships:
- No product substitutions are accepted without prior authorization by the appropriate Supply Chain representative.
- A “Request for a New Product and/or Product Trial Approval Form” is to be completed and approved before any new product or equipment is introduced for trial.
- Approval is granted by the Supply Chain Category Lead, in cooperation with Clinical Support and/or Biomedical.
- Suppliers may not provide unapproved product samples directly to or for patient use.
- For trial equipment that needs reprocessing, the supplier must give explicit cleaning instructions to reprocessing staff before or on delivery.
These are one organization’s rules. Another buyer’s policy may differ, so the order of steps in a given facility comes from that facility’s own procedures and contract terms, not from this page. For fallback sourcing when an item is unavailable, see backup supplier strategy and second sourcing, which separates a second source from a second distributor and notes that some items are hard to substitute.
Types and related concepts: who decides what
| Question | Who decides | Source |
|---|---|---|
| Is a different product accepted in place of the ordered one? | The buyer’s Supply Chain representative, before acceptance (PHSA policy) | PHSA vendor guidelines, products |
| Who approves a new product for trial? | The Supply Chain Category Lead, with Clinical Support and/or Biomedical (PHSA policy) | PHSA vendor guidelines, products |
| Does a change to a cleared device need a new 510(k)? | The manufacturer, through a risk-based assessment | FDA guidance, Oct 25, 2017 |
| Is a change of material supplier a change to assess? | The manufacturer, through its quality system | FDA guidance, Oct 25, 2017 |
Where it matters: what the FDA guidance does and does not cover
FDA’s guidance Deciding When to Submit a 510(k) for a Change to an Existing Device (issued October 25, 2017, nonbinding) addresses when a manufacturer’s change to its own device triggers a new premarket notification. It says that if there is any change in supplier or manufacturer material processing or finishing steps, the material change warrants further assessment, because biocompatibility depends not only on the materials but also on their processing, the manufacturing methods including sterilization, and manufacturing residuals. It adds that many material changes result from changes of material supplier, and that the manufacturer should use its quality system to analyze the change.
The guidance is written for manufacturers. It does not say that one brand can stand in for another, and a buyer cannot infer equivalence from it. What it shows a buyer is that a product can change upstream of the label.
Documents and terms that go with product substitution
The terms below are drawn from the PHSA policy, the FDA guidance and CASRAI’s own entries. The contract-level view is in the guide on a supply agreement template for medical supplies.
- Prior authorization: the buyer’s approval before a substitute is accepted (PHSA).
- Product or trial approval form: the PHSA form completed and approved before a new product or equipment is trialled.
- Cross-reference SKU: the vendor’s identification of the replacement for a discontinued item (CASRAI entry on vendor status codes).
- Specification match: confirmation that the substitute meets the same specification as the original (same CASRAI entry).
- Cleaning instructions: for trial equipment that needs reprocessing, supplied by the supplier on or before delivery (PHSA).
Common misunderstandings
- Treating a vendor’s offer as approved. In the PHSA policy, authorization comes before acceptance.
- Confusing a manufacturer change with a buyer’s substitution. The FDA guidance concerns the manufacturer’s change to its own device; it gives no permission to swap brands.
- Treating a sample as harmless. PHSA forbids unapproved samples directly to or for patient use.
- Overlooking the effect on supply counts. Different brands and substitutes change how stockouts are counted, as the stockout guide explains.
FAQ
What is product substitution?
It is a different item supplied in place of the one specified on an order or contract. Who may approve it depends on the buyer’s policy; under PHSA’s, prior authorization from Supply Chain is required.
How does product substitution work in a medical supply purchase?
Under the PHSA guidelines, the substitute is authorized before it is accepted, and new products for trial go through an approval form decided by the Supply Chain Category Lead with Clinical Support and/or Biomedical. Other organizations set their own procedures.
Which documents or terms go with product substitution?
Prior authorization, a product or trial approval form, a cross-reference SKU, a specification match and, for reprocessed trial equipment, supplier cleaning instructions. The section above names the source of each.
What mistakes do small buyers make with product substitution?
Accepting a substitute before authorization, treating FDA manufacturer-change guidance as buyer permission, and allowing unapproved samples near patients are the ones the sources cited on this page address.
Sources
- U.S. Food and Drug Administration, Deciding When to Submit a 510(k) for a Change to an Existing Device, guidance for industry and FDA staff, issued October 25, 2017; full text at https://www.fda.gov/media/99812/download; checked 2026-11-03.
- Provincial Health Services Authority (British Columbia), Supply Chain vendor guidelines: products, checked 2026-11-03.
