AAFCO is not a federal agency, but its standards have the force of law in most states because state feed-control officials adopt AAFCO model regulations directly. If you sell pet food, treats, or supplements in the U.S., AAFCO compliance is the operating standard.

Three areas matter most for private-label pet brands:

• Ingredient definitions: AAFCO publishes the Official Publication every year, which defines what each ingredient is and isn't. "Chicken meal" has a specific AAFCO definition; "natural flavors" has a definition; "meat by-products" has a definition. If you label an ingredient outside the AAFCO definition, state regulators will issue a stop-sale order.
• Nutritional adequacy claims: "Complete and balanced for all life stages" is an AAFCO-regulated statement. You can substantiate it two ways: formulation-method (the formula meets AAFCO nutrient profiles) or feeding-trial method (a six-month feeding trial conducted per AAFCO protocols). The two are not equivalent — feeding trials are higher-bar.
• Label format: AAFCO model regulations specify principal display panel content, guaranteed analysis format, ingredient declaration, feeding instructions, and statement of caloric content. Deviation triggers state enforcement.

For supplements and treats (which are not nutritionally complete), AAFCO classifies them as "specialty pet products" with slightly looser rules — but ingredient and label compliance is still required.