Prohibits the Treasury Secretary (through the IRS) from preparing most taxpayers’ returns or refund claims and treats any IRS-run electronic tax-prep service as if the Secretary prepared the return. It preserves returns prepared only through existing qualified return preparation programs or the IRS Free File Program. It also bars the Treasury/IRS from using funds, contracts, grants, or other agreements to develop or operate an electronic tax preparation service after enactment unless another law explicitly authorizes such activity. The return-preparation prohibition applies to returns filed more than 30 days after enactment.