Whole, unprocessed quinoa and amaranth seeds are classified under HTS Chapter 10 (cereals) or Chapter 12 (oil seeds and miscellaneous grains) depending on their primary use, while flours and processed forms fall under Chapter 11 or Chapter 19. The correct classification depends on the degree of processing and the product's commercial description. Misclassification between raw grain and processed ingredient headings can result in different duty rates and FDA entry review pathways, so consultation with a licensed customs broker is advisable.

All food facilities that manufacture, process, pack, or hold food for US consumption — including foreign grain exporters — must register with FDA under the Bioterrorism Act. Importers must also submit FDA Prior Notice before or at the time of arrival. Specialty grain shipments may be subject to FDA examination or sampling, particularly from origins with a history of mycotoxin or pesticide residue findings.