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Short answer: Substantial transformation is the test U.S. Customs and Border Protection (CBP) uses to decide whether processing in a second country changes an article’s country of origin. According to CBP, it occurs “if a new article with a different name, character, and use is created.” This page is general reference information, not legal advice or a ruling on any product.
Definition and scope
Under 19 CFR 134.1(b), the country of origin is the “country of manufacture, production, or growth of any article of foreign origin entering the United States.” The same paragraph adds that “further work or material added to an article in another country must effect a substantial transformation” for that other country to count as the origin. One point is easy to miss: 19 CFR 134.1 uses the phrase but does not define it. The working definition comes from CBP’s published guidance, which states the name, character and use formulation quoted above.
The test therefore asks a narrow question about a specific article: after the work done in the second country, is what comes out a different article from what went in, judged by its name, its character and its use?
How CBP and the FAR use the phrase
Marking and the ultimate purchaser
CBP’s marking rules in 19 CFR Part 134 require imported articles to show their country of origin to the “ultimate purchaser,” defined in 19 CFR 134.1(d) as “generally the last person in the United States who will receive the article in the form in which it was imported.” Section 134.1(d)(1) links this to the test: a manufacturer is the ultimate purchaser “if he subjects the imported article to a process which results in a substantial transformation of the article.” In practice, that is why the marking duty can stop at a manufacturer who transforms the import instead of following the article to the end customer. CBP’s informed compliance publication, Marking Country of Origin of U.S. Imports (last modified May 15, 2026; checked 2026-10-31), repeats both points.
Federal procurement
FAR 25.003 uses nearly the same words for buying, not marking. A “U.S.-made end product” is one “mined, produced, or manufactured in the United States” or “substantially transformed in the United States into a new and different article of commerce” with a name, character, or use distinct from that of the article or articles from which it was transformed. A “designated country end product” includes a WTO Government Procurement Agreement country end product, and that prong repeats the same wording for transformation “in a WTO GPA country.” Whether an item meets these definitions is what drives the Trade Agreements Act and Buy American analyses covered in the site’s guides on Trade Agreements Act compliance and TAA designated countries.
One phrase in three rule sets
| Rule set | What it decides | Where the phrase appears |
|---|---|---|
| CBP marking, 19 CFR 134.1 and CBP guidance | Which country is named on the marking, and who the ultimate purchaser is | Work in another country “must effect a substantial transformation”; a manufacturer who transforms the import is the ultimate purchaser; CBP says a transformation creates “a new article with a different name, character, and use” |
| FAR 25.003 | Whether an end product is U.S.-made or a designated country end product | “substantially transformed in the United States [or a WTO GPA country] into a new and different article of commerce” with a distinct “name, character, or use” |
| 19 CFR Part 102, Rules of Origin | Country of origin of imported goods under the NAFTA/USMCA-related rules, including for marking | Part 102 sets out its own codified rules for determining the country of origin of imported goods, including for marking under USMCA |
The practical lesson of the table: the same words appear in marking and in procurement, but they answer different questions, and a separate codified rule set (19 CFR Part 102) exists for USMCA-related goods. An answer under one regime should not be copied to another without checking the governing text. Marking rules are covered in country-of-origin marking for imported medical devices.
Where it matters for labs and clinics
Labs and clinics meet the test indirectly. A federally funded purchase may be subject to Buy American or Trade Agreements Act conditions, as discussed in the guide to Buy American compliance for federally funded medical equipment. In those cases, the FAR definitions turn on where an article was substantially transformed into a new and different article of commerce. A checklist drawn from the rules above:
- Ask which country the article was last transformed in, and whether that work produced an article with a different name, character and use than the inputs.
- Separate the three questions: the marking country (CBP), the FAR end-product category (procurement), and any USMCA-related origin determination (Part 102).
- Remember that the CFR text itself does not define the phrase, so a vendor’s statement that an item is “substantially transformed” is a claim to be supported, not a definition.
- For a binding answer on a particular product, the matter belongs with the contracting officer, customs counsel or a CBP ruling process, not with this page.
Common misunderstandings
- “The CFR defines it.” Not in 19 CFR 134.1, which uses the phrase without defining it; the name, character and use wording is in CBP’s guidance and in FAR 25.003.
- “Any work in a second country changes the origin.” Per 19 CFR 134.1(b), the further work must effect a substantial transformation, and CBP’s wording requires a new article with a different name, character and use.
- “Marking and procurement origin are the same thing.” They use closely similar language but sit in different regulations with different purposes, as the table shows.
Frequently asked questions
What is substantial transformation?
It is the test for whether work done in a second country makes a new article with a different name, character and use, which per CBP changes the country of origin to that second country.
Does 19 CFR 134.1 define substantial transformation?
No. It states that further work must effect a substantial transformation but does not define the term; CBP’s guidance supplies the name, character and use formulation.
Who is the ultimate purchaser if a manufacturer processes the import?
Under 19 CFR 134.1(d)(1), the manufacturer is the ultimate purchaser if its process results in a substantial transformation of the imported article.
Sources
- 19 CFR 134.1, Definitions, Legal Information Institute, law.cornell.edu/cfr/text/19/134.1 (checked 2026-10-31).
- CBP, Marking Country of Origin of U.S. Imports, cbp.gov informed compliance publication (last modified May 15, 2026; checked 2026-10-31).
- FAR 25.003, Definitions, acquisition.gov/far/25.003 (checked 2026-10-31).
- 19 CFR Part 102, Rules of Origin, law.cornell.edu/cfr/text/19/102.0 (checked 2026-10-31).
