The Environmental Protection Agency (EPA) is taking final action to approve revisions to the State Implementation Plan (SIP) submitted on November 29, 2021, by the State of Missouri. This final action approves revisions to a state regulation related to the Cross- State Air Pollution Rule SO<INF>2</INF> Group 1 Trading Program. The revisions alter the amounts of CSAPR SO<INF>2</INF> Group 1 emission allowances that are allocated to two of the state's units from the state's annual emissions budgets. Additionally, the revisions make non- substantive revisions to rule language that excludes certain provisions in the Code of Federal Regulations from incorporation by reference into the state's regulations. Approval of these revisions will ensure Federal enforceability of the State's rules. The EPA's approval of these SIP revisions is being done in accordance with the requirements of the Clean Air Act (CAA).