The Form 1040-X for amending a 2025 federal tax return is estimated to be available in TurboTax on 03/04/2026
Not until the IRS updates the Form 1040-X instructions for tax year 2025 can TurboTax provide a 2025 Form 1040-X.
Current IRS Form 1040-X instructions are for tax year 2024 - https://www.irs.gov/pub/irs-pdf/i1040x.pdf
IRS Draft Form 1040--X instructions for tax year 2025 - https://www.irs.gov/pub/irs-dft/i1040gi--dft.pdf