This final rule makes revisions to the pesticide tolerance crop grouping regulations. Crop grouping allows tolerances to be established for multiple related crops based on data from a representative set of crops. The revisions will create a new crop group for edible fungi (mushrooms), expand existing crop groups by adding new commodities, establish new crop subgroups, and revise the representative crops in some groups. Additionally, EPA is revising the general crop group regulation to explain how the Agency will implement revisions to crop groups. EPA expects these revisions to promote greater use of crop groupings for tolerance-setting purposes and, in particular, assist in retaining or making pesticides available for minor crop uses. This is the first in a series of planned crop group updates expected during the next several years.