--- title: "Tissue Reference Group: How FDA Decides 361 Vs 351" description: "Tissue Reference Group explained: how FDA's TRG decides whether an HCT/P is regulated under section 361 or 351, and what that means for banked adipose tissue." url: "https://savemyfat.com/tissue-reference-group-fda-361-351/" --- # FDA’s Tissue Reference Group: Who Decides Whether a Tissue Product Is 361 or 351 Table of Contents - [Oscar Tellez](https://savemyfat.com/oscar-tellez/) - October 21, 2026 - 10:00 am - [Regulation](https://savemyfat.com/category/regulation/) ![Three binders, a laptop and a microscope in a glass walled lab office, a setting for the tissue reference group](https://savemyfat.com/wp-content/uploads/2026/09/tissue-reference-group-fda-361-351.webp)Fda's tissue reference group: who decides whether a tissue product is 361 or 351 2 Patients hear the numbers 361 and 351 and ask a fair question: who at FDA actually decides which one applies to a cell or tissue product? The answer is a standing committee called the Tissue Reference Group. This post explains what the group is, how a question reaches it, the four criteria it applies, what it does not do, and why that matters for anyone who has preserved their own adipose tissue. **TLDR The Tissue Reference Group is a six member FDA committee drawn from CBER and CDRH that recommends whether a human cell or tissue product meets the four criteria in 21 CFR 1271.10(a) or fits an exception. It responds in writing and does not approve or license anything. Banking adipose tissue preserves tissue only and does not guarantee any future use, which depends on regulatory status and physician guidance at that time.** **Important Disclaimer:** Save My Fat does not provide FDA-approved treatments or cures for any disease. Banking adipose tissue today does not guarantee eligibility, access, or clinical benefit from any future therapy, clinical trial, or medical program. FDA’s list of approved cellular and gene therapy products includes no adipose-derived product. All content is for educational purposes only and does not constitute medical advice. Patients must consult their own licensed healthcare professionals regarding all medical decisions. --- Whether stem cell therapy is legal, and where, is the question readers bring to this site more than any other. The honest answer starts with a classification, not a state. A product made from human cells or tissue falls on one of two regulatory paths, and four criteria in a federal regulation draw the line. Few people know that FDA has a named group whose job is to apply those criteria to real products. That group is the Tissue Reference Group, usually shortened to TRG. This post stays with what FDA’s own pages and the regulation say, and it does not claim that any stored tissue has a particular classification today. ## What the Tissue Reference Group Is The Tissue Reference Group is an FDA committee that recommends how a specific human cell or tissue product should be regulated. According to the [TRG page](https://www.fda.gov/vaccines-blood-biologics/tissue-tissue-products/tissue-reference-group), FDA created it under its 1997 “Proposed Approach.” Its membership is “three representatives from the Center for Biologics Evaluation and Research (CBER) and three from the Center for Devices and Radiological Health (CDRH),” with liaisons from the Office of Combination Products and the Office of the Chief Counsel. The group recommends on three questions: whether a product meets the four criteria in 21 CFR 1271.10(a), whether an exception in 1271.15 applies, and which regulations otherwise govern the product. FDA’s [SOPP 8004](https://www.fda.gov/media/85648/download), Version 6, dated February 27, 2023, sets out the procedure. One line matters for anyone waiting: “The TRG generally responds in writing to the inquirer within 60 days of receipt by the Executive Secretary of an inquiry that contains sufficient detail for evaluation.” A vague question does not start the clock. --- ## How a Question Reaches the Tissue Reference Group A question reaches the group as a written request, sent by email to [[email protected]](/cdn-cgi/l/email-protection) or by fax to 301-595-1303. The FDA page lists both routes. The request needs enough detail about the product for the members to evaluate it against the criteria. An older fast lane no longer exists. FDA states that “The Tissue Reference Group (TRG) Rapid Inquiry Program (TRIP) ended March 31, 2021.” The [TRIP page](https://www.fda.gov/vaccines-blood-biologics/trg-rapid-inquiry-program-trip) lists the alternatives as the standard TRG process, a Request for Designation, and a Pre-Request for Designation. SOPP 8004 also states that an inquirer dissatisfied with a TRG recommendation may file a Request for Designation, so the group’s reading is not the only formal step available. --- ## What the Four Criteria Are The four criteria sit in [21 CFR 1271.10(a)](https://www.ecfr.gov/current/title-21/chapter-I/subchapter-L/part-1271/subpart-A/section-1271.10), and a product must meet all four. The first is that the product “is minimally manipulated.” The second is that it “is intended for homologous use only, as reflected by the labeling, advertising, or other indications of the manufacturer’s objective intent.” The third is that its manufacture “does not involve the combination of the cells or tissues with another article, except for water, crystalloids, or a sterilizing, preserving, or storage agent.” The fourth has two branches. Either the product has no systemic effect and does not depend on the metabolic activity of living cells, or it is for autologous use, use in a relative, or reproductive use. Under 1271.10(b), such establishments “must register with FDA.” The first two criteria rest on definitions in [21 CFR 1271.3](https://www.ecfr.gov/current/title-21/chapter-I/subchapter-L/part-1271/subpart-A/section-1271.3). For cells or nonstructural tissues, minimal manipulation means “processing that does not alter the relevant biological characteristics of cells or tissues.” Homologous use means “the repair, reconstruction, replacement, or supplementation of a recipient’s cells or tissues with an HCT/P that performs the same basic function or functions in the recipient as in the donor.” This site explains what [minimally manipulated](https://savemyfat.com/what-minimally-manipulated-really-means-under-1271/) means in practice and why the [homologous use criterion](https://savemyfat.com/homologous-use-361-criterion-physicans-cant-ignore/) is so often at issue. One exception sits beside the criteria. Under [21 CFR 1271.15(b)](https://www.ecfr.gov/current/title-21/chapter-I/subchapter-L/part-1271/subpart-A/section-1271.15), an establishment that removes cells or tissue from an individual and implants them into the same individual “during the same surgical procedure” is not required to comply with Part 1271. The text defines no time limit. --- ## 361 Versus 351: What the Determination Changes The determination changes which rules govern a product and what must exist before it can be distributed. A product that meets all four criteria is regulated under Part 1271, which addresses communicable disease, not clinical value. A product that fails a criterion can be treated as an unapproved drug or an unlicensed biological product, as FDA stated in its 2026 warning letters. The table sets the two paths side by side. Question Meets all four criteria (361) Fails a criterion (351) Governing rules 21 CFR Part 1271 Drug and biological product law Focus Communicable disease, not clinical value Unapproved drug, unlicensed biologic Before distribution Register and list with CBER, follow Part 1271 Approved BLA, or an IND in effect Who reads the criteria TRG recommends; Request for Designation available Same starting point The table describes categories, not any particular product. A 351 finding means a product needs an application that FDA reviews, not just registration. --- ## What the Tissue Reference Group Does Not Do The group does not approve products, issue licenses, or decide whether a product is safe or works. It recommends a regulatory category. A written TRG response tells an inquirer which rules apply; it is not permission to market and not a finding of clinical benefit. The group also does not have a public record of decisions that this post can point to. FDA’s TRG page and SOPP 8004 do not mention annual summaries, so this post makes no claim about what the group has decided across the industry. Because the criteria turn on how a product is made and marketed, a change in processing or advertising can change the answer. --- ## Why the Tissue Reference Group Matters for Banked Adipose Tissue The Tissue Reference Group matters for banked adipose tissue because the same four criteria would govern any future product made from it, and banking decides none of them. Preserving adipose tissue is storage of the patient’s own tissue. Whether any later product meets the criteria depends on what is done to it and what it is intended for at that time. That is why this post does not say banked adipose tissue is one category or the other. Part 1271 defines an HCT/P as “articles containing or consisting of human cells or tissues that are intended for implantation, transplantation, infusion, or transfer into a human recipient,” and its examples do not name adipose tissue. The broader rules are covered in this site’s guide to [adipose tissue regulations](https://savemyfat.com/understanding-fda-regulations-for-adipose-tissue/). The practical lesson is to ask questions rather than accept labels. Ask a bank whether it is registered under [21 CFR Part 1271](https://savemyfat.com/what-is-21-cfr-part-1271-and-why-it-governs-tissue/), what is done to the tissue, and what the storage agreement says about future use. Those answers must come from the bank itself. Any future use depends on FDA regulatory status, physician guidance, and the availability of approved or investigational pathways at that time. --- ## Frequently Asked Questions ### Does the Tissue Reference Group approve stem cell products? No. The group recommends whether a product meets the four criteria in 21 CFR 1271.10(a) or fits a 1271.15 exception, and which regulations otherwise apply. A TRG response is a written recommendation, not an approval or a license. ### Can a patient ask the TRG about their own banked tissue? The FDA page describes inquiries with “sufficient detail for evaluation” of a product. Stored tissue with no defined product or intended use gives the group little to evaluate. Questions about stored tissue belong with the bank and the patient’s own licensed provider. ### Is the TRIP program still available? No. FDA states that the TRG Rapid Inquiry Program ended March 31, 2021. The alternatives FDA lists are the standard TRG process, a Request for Designation, and a Pre-Request for Designation. --- ## Key Takeaways The Tissue Reference Group is an FDA committee of three CBER and three CDRH representatives that recommends whether a cell or tissue product meets the four criteria in 21 CFR 1271.10(a) or fits a 1271.15 exception. Detailed inquiries generally get a written response within 60 days, and a dissatisfied inquirer may file a Request for Designation. The TRIP program ended March 31, 2021. The group approves nothing. Banked adipose tissue is preserved tissue, and any future use depends on those criteria, FDA status, and physician guidance at that time. Save My Fat connects patients and providers with a U.S.-based tissue bank. It is not a tissue bank, a laboratory, a medical practice, or a treatment provider. Stem cell and regenerative medicine regulations vary by state, including specific informed-consent and disclosure requirements in Florida, Utah, California, Georgia, and Tennessee governing tissue and stem cell services. Banking adipose tissue does not connect patients to any treatment pathway, and any future use depends on FDA regulatory status, physician guidance, and the availability of approved or investigational pathways at that time. Readers weighing adipose tissue banking for potential future use can review the [pricing page](https://savemyfat.com/pricing/) or send a question through the [contact page](https://savemyfat.com/contact-us/). --- *Save My Fat works with a U.S.-based tissue bank for laboratory processing and storage.* *This article is for educational purposes only and does not constitute medical or legal advice. Please consult your own licensed healthcare provider before making any decisions about treatment or research participation.* **About the author:** Oscar Tellez is the founder and CEO of Save My Fat. He holds a Bachelor of Science in Exercise Science and Health Promotion from Florida Atlantic University. He has spent a decade in the regenerative medicine industry across product distribution, laboratory and vendor relationships, and provider training. He is not a licensed clinician, and this article is educational, not medical advice. **Related guide:** [FDA adipose tissue regulation](https://savemyfat.com/fda-regulation-adipose-tissue/). Follow Save My Fat on Google Set us as a preferred source and Google will show our latest updates more often in your results. [PrevPreviousCord Blood Banking vs Adipose Banking: What Applies to You as an Adult](https://savemyfat.com/cord-blood-vs-adipose-banking/) [NextWhat Happens to Banked Tissue If You Die: Next of Kin, Directives, and the Storage AgreementNext](https://savemyfat.com/banked-tissue-succession-planning/) Adipose Banking ### [What Happens to Banked Tissue If You Die: Next of Kin, Directives, and the Storage Agreement](https://savemyfat.com/banked-tissue-succession-planning/) [Read More »](https://savemyfat.com/banked-tissue-succession-planning/) Oscar Tellez 10/22/2026 10:00 AM [![Three binders, a laptop and a microscope in a glass walled lab office, a setting for the Tissue Reference Group](https://savemyfat.com/wp-content/uploads/2026/09/tissue-reference-group-fda-361-351-768x768.webp)](https://savemyfat.com/tissue-reference-group-fda-361-351/) Regulation ### [FDA’s Tissue Reference Group: Who Decides Whether a Tissue Product Is 361 or 351](https://savemyfat.com/tissue-reference-group-fda-361-351/) [Read More »](https://savemyfat.com/tissue-reference-group-fda-361-351/) Oscar Tellez 10/21/2026 10:00 AM [![Frosted glass cold storage cabinet with a clipboard, a storage scene for comparing Cord Blood vs Adipose banking](https://savemyfat.com/wp-content/uploads/2026/09/cord-blood-vs-adipose-banking-768x768.webp)](https://savemyfat.com/cord-blood-vs-adipose-banking/) Adipose Banking ### [Cord Blood Banking vs Adipose Banking: What Applies to You as an Adult](https://savemyfat.com/cord-blood-vs-adipose-banking/) [Read More »](https://savemyfat.com/cord-blood-vs-adipose-banking/) Oscar Tellez 10/20/2026 10:00 AM Regulation ### [FDA’s 2026 Plausible Mechanism Draft Guidance: What It Could Mean for Autologous Cells](https://savemyfat.com/plausible-mechanism-guidance-fda-2026/) [Read More »](https://savemyfat.com/plausible-mechanism-guidance-fda-2026/) Oscar Tellez 10/19/2026 10:00 AM Regulation ### [Tissue Recalls: How an HCT/P Recall Works and What It Would Mean for Banked Tissue](https://savemyfat.com/tissue-recall-hctp-banked-tissue/) [Read More »](https://savemyfat.com/tissue-recall-hctp-banked-tissue/) Oscar Tellez 10/16/2026 10:00 AM Regulation ### [Which States License Tissue Banks, and Why It Matters for Your Banked Tissue](https://savemyfat.com/tissue-bank-licensing-by-state/) [Read More »](https://savemyfat.com/tissue-bank-licensing-by-state/) Oscar Tellez 10/15/2026 10:00 AM ```json [{"@context":"https:\/\/schema.org","@graph":[{"@type":"BreadcrumbList","@id":"https:\/\/savemyfat.com\/tissue-reference-group-fda-361-351\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":"1","item":{"@id":"https:\/\/savemyfat.com","name":"Home"}},{"@type":"ListItem","position":"2","item":{"@id":"https:\/\/savemyfat.com\/our-blog\/","name":"Our Blog"}},{"@type":"ListItem","position":"3","item":{"@id":"https:\/\/savemyfat.com\/category\/regulation\/","name":"Regulation"}},{"@type":"ListItem","position":"4","item":{"@id":"https:\/\/savemyfat.com\/tissue-reference-group-fda-361-351\/","name":"FDA’s Tissue Reference Group: Who Decides Whether a Tissue Product Is 361 or 351"}}]}]},{"@context":"https:\/\/schema.org","@graph":[{"@type":"Person","@id":"https:\/\/savemyfat.com\/oscar-tellez\/#person","name":"Oscar Tellez","jobTitle":"Founder","description":"Oscar Tellez is the Founder of Save My Fat, a company that connects patients and physicians with a U.S. tissue bank for adipose tissue banking, so a person's own tissue can be preserved for potential future use in FDA-regulated pathways. 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