This letter responds to a request for an analysis of the distributional effects of the 2025 reconciliation bill. CBO and the staff of the Joint Committee on Taxation have recently estimated the budgetary effects of the One Big Beautiful Bill Act, as ordered reported by the House Committee on the Budget on May 18, 2025. CBO allocated the effects on revenues and spending to households. The agency also allocated to households the effects of states' estimated responses to changes to Medicaid and the Supplemental Nutrition Assistance Program. This is a preliminary analysis and will be updated if practicable.