President Trump cannot repeal the ACA by executive order. The ACA is a statute, enacted by Congress, which under the Constitution only Congress can repeal or modify. Furthermore, the order does not itself change existing regulations. Rather, it provides instructions or guidelines as to how Trump wants responsible agencies to exercise their discretion in interpreting and applying statutory requirements. The order appropriately recognizes that the new priorities it outlines can be followed by administration officials only “to the maximum extent permitted by law.”

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