USDA Revises the Mushroom Grade Standards

The U.S. Department of Agriculture's (USDA) Agricultural Marketing Service (AMS) is revising the United States Standards for Grades of Mushrooms, at the industry's request, to align with current marketing trends and provide industry with uniformity when marketing mushrooms.

AMS is amending the standards to (1) add a grade for portabella mushrooms, (2) remove size from the criteria for each grade and create a separate section for size, (3) revise the tolerances for defects - consistent with modern production and handling practices, and (4) update terminology, definitions, and defect scoring guides. These revisions will ensure the standards align with current marketing trends and provide industry with uniformity when marketing mushrooms.

The final notice will be published in the Federal Register on Aug. 25, 2026. The new standards go into effect Sept. 24, 2026 and can be viewed on the AMS website on or after this date.

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