The U.S. Department of Agriculture’s (USDA’s) Agricultural Marketing Service (AMS) issued two final guidance documents providing industry stakeholders with instructions on how to implement certain requirements of the National Bioengineered Food Disclosure Standard (NBFDS). The agency’s Guidance to Ensure Acceptable Validation of a Refining Process outlines steps for validating that a refining process makes modified genetic material undetectable in a food. AMS’s Guidance on Testing Methods provides considerations for the selection of a test method to ascertain that a food or ingredient does not contain detectable modified genetic material and therefore does not require a bioengineered food disclosure. AMS issued draft versions of the guidance documents in December 2019 and February 2020, respectively. AMS also issued new Frequently Asked Questions (FAQs) corresponding to each of the guidance documents. This memorandum summarizes the guidance documents and FAQs, but we encourage any entity relying on the use of a validated refining process or testing to establish that a food is not subject to disclosure under the NBFDS to read the documents in their entirety.