The 2020 USDA-HHS Dietary Guidelines Advisory Committee Report and other prominent medical associations (NIH, AAP, AAAAI) recommend starting babies as early as 4 months of age with food allergen introduction.
We recommend starting the Stage 1 introduction, and Stage 2 for continued exposure together anytime between 4 and 11 months of age. You should sustain exposure to Stage 2 for at least 6 months, or until your baby is eating solids, and ready to move on to Stage 3.
Stage 3 is designed as the next step from Stage 2 and expands allergen exposure from 3 to 9 allergens including tree nuts, sesame, wheat, and soy. This stage is recommended once your baby is consistently eating solids. If your baby hasn't started allergen introduction but is already eating solid foods, feel free to start with Stage 3.